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Oil boiler DHW among other "issues"

Just moved into "new to us" home in northern CT.  I already discovered a leak in the heating system and fixed it.  It was on the 2nd floor buried behind a wall and a cast iron tub, hahahaha!! 

My top priority is figuring out why my hot water is hot coming out of the coil and then luke warm coming out of the mixing valve with the mixing valve set to any number 120-160. there are also a few other issues i would like to address.

*

Setup:

1800 sf colonial - 2 zones plus DHW coil

weil-mclain WTGO-3 w/tankless coil and Beckett AFG burner

Honeywell L7224 aquastat(2006 - pre-adjustable Hld) 

    Original setting Hi 185  Lo 165  Ldf 10

    Currentl setting Hi 170  Lo 150  Ldf 10 

Watts 70A mixing valve after tankless coil

copper baseboard lining 75% of the home's exterior

*

1)  DHW - using a 2.5gpm showerhead the temp fluctuation is crazy huge, from really hot when the boiler is done firing, and really cold at the low limit.  The thing is, at the boilers coldest temp, the pipe on the coil outlet is still extremely hot, it's just the water after the mixing valve that's cold.  I wonder, do you think the mixing valve is stuck and not properly adjusting the flow as it should?  Or maybe it's improperly installed?  I noticed the installation is a straight up trap approx 6" below tankless output and has no check valve on the cold water side to compensate for the pressure drop of the coil for the hot water.  Could this be the cause?  Should I replace the tempering valve with a better mixing valve such as the MMV? Suggestions?

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2)  I have noticed that the burner fires with EVERY call for heat.  My understanding is that the burner was only supposed to fire if the boiler temperature was below the HL - Hld (fixed at 10 for this aquastat).  This causes the boiler to run for maybe a minute before the thermostat is satisfied and then turn off.  The boiler seems to run for about 1-2 minutes 2-3 times per hour.  For example: HL=170 Boiler temperature=169, thermostat call for heat and the burner still fires.  Should it? Is this a problem? How can i solve it? Wiring issue?

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3)  The baseboards are off so long that they cool down to room temp, 65.  When there is a call for heat, the circulator and burner kick on first, then the cold water from the baseboards rushes into the boiler.  I have observed a 15 degree drop on average when this happens.  Because the thermostat is satisfied so quickly, it seems the boiler temp remains a few degrees above the lower limit until the next call for heat since it never fires long enough to get back up to where it was.  Is this a problem or more due to the fact it's mild fall weather and the system is designed for the dead of winter?

*

4) Curious - I feel like i could heat my home confortably for 70% of the heating season with 120 degree water through the baseboards, maybe a little higher.  If i was to add a HW tank to the system, could i accomplish low boiler temps like that with this boiler?  Would it be safe for the boiler? Would it be an effective way to reduce oil consumption?

 

Thank you for taking the time to read this and any assistance is greatly appreciated.
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Comments

  • Al Letellier_21
    Al Letellier_21 Member Posts: 402
    heating system set up

    You certainly have some issues with that system, and it would be difficult to solve them all with a post as a lot of information is missing and not seeing is a problem, but...It sounds like the aquastat is not properly set and the mixing valve is not installed correctly. I would set the hi limit at 190 and the low at 170. The 70A mixer should be at least 8-10" BELOW the coil, have a flow restrictor installed on the cold water inlet BEFORE the mixing valve AND the coil, and it does sound like the element may be toast. I would recommend getting a good heating guy in there to look things over.

    As to adding an indirect, I had the same set up as you, but in a smaller home,and I went to an indirect with outdoor reset and cut my fuel consumption 50%. Weil recommends that the boiler run at a min of 140 to prevent condensation so reset savings are not there on mild spring and fall days, but there are ways around that too. A good heating guy can help you there as well. Check the Find a Pro to locate on in your area. Good luck
  • Ironman
    Ironman Member Posts: 6,890
    Tankless Coil

    In addition to the good advice that Al gave, I would also check the tankless coil. It may be scaled up and restricting flow.



    An indirect and outdoor reset is the way to go.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • Patchogue Phil_2
    Patchogue Phil_2 Member Posts: 303
    Tell us the ways, please.

    Weil recommends that the boiler run at a min of 140 to prevent

    condensation so reset savings are not there on mild spring and fall

    days, but there are ways around that too
    .



    Can you elaborate,  please?  I am sure there are many more like me who would like to know how to save fuel on not so cold days.  What are the ways?
  • NRT_Rob
    NRT_Rob Member Posts: 1,013
    edited November 2010
    actually

    I believe brookhaven's studies seem to indicate that with high mass boilers with or without coils, stand alone water heaters are almost 50% more efficient.



    I have stopped recommending indirects on cast iron boilers. way too much energy lost at the end of the heat demand cycles. in the winter, that heat will probably be utilized for heating, but that still leaves over half the year where you are wasting a lot more energy than you should, worse in milder climates.



    attached study, "performance of integrated hydronic systems", 2007, page 12 is interesting, brookhaven national labs



    edit: I'm only talking about DHW production here, not heating, sorry!
    Rob Brown
    Designer for Rockport Mechanical
    in beautiful Rockport Maine.
  • Ironman
    Ironman Member Posts: 6,890
    Brookhaven Report

    Rob,

    Correct me if I'm wrong, but I believe the report does not take into consideration the savings that would be realized if the cast iron boiler with the indirect had outdoor reset vs. the boiler with the tankless without reset. That could easily be a 30% or more savings over the tankless boiler.



    Add the post heat purge feature which some manufacturers offer and the results are even better.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • icesailor
    icesailor Member Posts: 7,265
    Issues:

    While what has been said is apparently true, I think that there are other "issues" when the question is about the hot water and the operation of the system.

    It sounds to me that the water coming out of the tankless is hot, very hot. There is no mention that the water is cold after it leaves the tempering valve. But the water isn't hot or very hot at the hot water inlet of the mixing valve.

    This is a plumbing issue. Not a heating issue.

    I understand that the shower valve is a single lever. If it is a Symmons, the balancing spool is stuck part way across. If it is stuck all the way across, it won't pass water. It is a safety device. If it is any type of modern single lever that isn't a Moen that says "Moentrol" on the cover, the balancing spool is stuck.

    If the hot water to the valve is drastically cooler than what comes to the shower, and water at other fixtures are hotter, you may have a toilet tempering valve that is stuck open. Hope that if this is the case, someone can find it if it is buried in a wall. "I" could find it. Someone else, not hopefully.

    As far as your boiler settings, there isn't a lot of water in that WTGO-3. There are only so many BTU's in a .85 GPH nozzle. I doubt that there is much more than 3 gallons of water in the boiler. That amount of water or say 5 gallons for discussion, is the medium you heat up to heat the water in the coil. Set the HI limit on the control to 190. The only time you will get 190 degree water is if the thermostat calls for heat. Set the LOW/CIRC to 170 degrees. That is what the temperature will be when you need domestic hot water.

    If you understand about rising and falling outside temperatures, and their relationship to heating water temperatures, you will know that mostly, in a year, you don't need any radiation, of very little of what you have already installed. And you are only heating 3 to 5 gallons of water.

    Over my many years, I have tried a lot of different things that were supposed to save money on heating fuel. I never saw any of them do anything appreachible except set back thermostats and using a tankless with a storage tank. And "I" stop for pennies. A dollar bill in the road and I slam on the brakes.

    If you have a old, drafty house, you will want to have the boiler water warm. Feels some nice to feel the warmth when you turn up the T-stat.

    I hear a lot of guys claim all these great savings from the latest idea. No one has proven anything to me.

    On Interstate 95, driving to Florida, my car gets 28 MPG driving at 70 MPH for a long distance. If I jump it up to 80 MPH, it goes to 26.8 MPG. BFD.

    But I get there (1500 Miles from my home) in almost 3 hours, less. Without stops or delays. With stops and delays, it is 24 hours. Every year, both ways.

    Stops and delays equal all those perceived savings.

    JMO,
  • icesailor
    icesailor Member Posts: 7,265
    Issues/Brookhaven:

    So, what you and BHL are saying is that if I use 1000 gallons of oil a year, and I have  tankless with a storage tank, and I switch it to a Indirect, I will save 300 gallons of oil per year. Never happen. I have seen savings of something when I added a storage tank to a tankless and dropped he temperature in the system. And added set back thermostats. But no where along the lines of 30%.

    Never ever happen.

    30% of what? is what I ask.

    Joe the wino was shuffling down the street. Happy. Not a penny to his name. He spotted a dime in the gutter. On picking it up, he reflected how his lot and wealth in live had increased ten times. He then found another dime. He doubled his wealth. But he was only worth 20 cents. Four returnable containers would double it again. Big deal.
  • Ironman
    Ironman Member Posts: 6,890
    Please Don't Mis-Quote Me !

    Icesailor,

    Nothing was mentioned about connecting a storage tank to a tankless coil and then switching that to an indirect. Those are your thoughts, not my words.



    My observation was that the study did not take into consideration the savings that could be realized with a system that has outdoor reset vs. one that doesn't.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • icesailor
    icesailor Member Posts: 7,265
    Outside re-set:

    Sorry to keep on here but,

    The problem with "outdoor reset" is that it works a lot better on paper and in theory than in actual practice.

    If you use outdoor reset in a area with high varying winds, your reset curves go down the commode. I know. Been there, seen that. Because where I work, I/we use 0 degrees with 15 MPH wind, if it is 35 out and blowing 15, you are at 1/2 of your design temperture. But if the wind drops, you are over temperature. If the wind picks up to a steady 30 with gusts to 45, you are under temperature. If it is zero, and it is gusting to 45 MPH (seen that more than once), you are way below your design temperature. The cost of any equipment to allow and correct for this would negate any fuel savings.

    There are many factors in infiltration that you can not allow for. And when confronted with it, your only way out is to raise the water temperature in the system. If you have ever designed and installed a heating system (like I have and do) where you know that everything is right and everything works. Then, you get a irate call on a day when it is 28 degrees and blowing 35 MPH outside. The house won't go over 62 when the thermostat is set at 70. The boiler is cycling off and although you dsigned it for 180, 220 won't get it over 62 and the return water is 200 degrees. Come back a few days later and it is 15 degrees out with no wind. The house is at 70 and the circulator is cycling on and off to the thermostat. The reason? Excessive infiltration due to building code requirements. Recessed ceiling lights in a ceiling with ventilated attic space above and soffit and ridge vents on cathedral ceilings.

    Your best tool is a infra-red thermometer gun to shoot the walls and ceilings. When you find a flat ceiling with 55 degree ceiling temperatures and temperatures in the can lights of 35 or 40 degrees, it aint your fault. You are looking at a "cold sink". But explain it after some "expert" has told the client that YOU screwed up their heating system and the boiler and radiation is undersized and needs to be replaced. That's if the client bothers to tell you. He may just get the idiot to do the work and they can all bad mouth you. They might even try to ask you to pay for the correction of "your mistake". Nothing will be said when the problem isn't solved from lack of understanding of the problem.

    Set back thermostats artificially raise and lower the outside temperature.

    If you run a clod start oil boiler, and it gets dirty, and it will, there go ANY savings you made from anything. Warm starts do not get dirty.

    Sorry for the rant.
  • icesailor
    icesailor Member Posts: 7,265
    Misquotes:

    Iron,

    I wsn't misquoting you.

    I just hear all forms of this stuff. I was reaponding to just my thoughts.

    I'm sort of on a rant. I'm in FLA until 11/30. I got some sort of virus or mal-ware from somewhere that has really wrecked havoc on my 'puter. I think the stuff is still there. I have paid a bit to get it fixed and I don't think it is. All my virus protectin is automatic and up to date. I have to pay them $90.00 to remove the stuff that got by their stuff, someone hacked my Yahoo account, changed my password and personal information so I can't repair it, and I have spent three weeks trying to deal with tech's in India that send form replies to me about getting back in 24 hours. My old ISp is no longer and fortunately, I have had a AOL account since 1995 that I can use. I went to a ATT store to have them download the latest version of ATT communication manager for my wireless air card device and the virus protection told us that their program was infected with viruses and would ruin my hard drive. So I tooi it to Office Depot here in FLA and they did some magig on it. I don't think they found anything but it cost me $170.00. Meanwhile, I have no E-mail and no way to get to my customers, and when I get back to MA, I'll probably have to re-format my gard drive, back up what I can save and hope to not get re-infected.

    I'm having a wonderful time in FLA. Where I hate the heat. Next month, I hope to get in some sailing. It's getting colder.
  • Ironman
    Ironman Member Posts: 6,890
    No Offence Taken

    I hope you get things straightened out with your computer. Seems like there are few things more frustrating than a un-cooperative PC. I think we've all been drawn into being too dependent on these things.  I couldn't get this on to copy a page earlier today and still can't figure out what's wrong.



    Have a safe trip home.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • Jean-David Beyer
    Jean-David Beyer Member Posts: 2,666
    more frustrating than a un-cooperative PC.

    "Seems like there are few things more frustrating than a un-cooperative PC."



    There is one thing more frustrating: and incompetent PC repairer. You pay them time and money to fix your computer, and after doing that, it is no better than when you started. Of course, this applies to knuckleheads in any profession, including car mechanics, doctors, heating contractors, ... .



    I do not know what to do about it.
  • ice4life1417
    ice4life1417 Member Posts: 30
    update and question

    1) So I did a little plumbing. I put in a ball valve immediately before the cold water inlet to the tempering valve and closed it about 80% to restrict the amount of cold water which could mix. at 170/150, we now have plenty of hot water for the shower. PLENTY!!! The fluctuation is still there though, the result of a horrible mixing valve i think. Tried replacing the guts and got the same result, oh well. At least we have hot water.



    2) I never should've posted this one as a problem. Apparently that's exactly what the 7224 does as normal operation. I read the installation instructions and wiring diagrams.



    3) After a few really cold days, this seems to be an issue only when it is much more mild weather. Perils of sizing for the coldest day when the temperatures vary from 0 to 100 year round.



    4) I'm considering feeding an electric water heater through the tankless coil (setting my low to 140 for the heating season, and shut the boiler off for the summer. My thoughts are: this would put the main hot water supply 20 ft closer to the kitchen/baths. It would require electricity for only maintaining the temperature during the heating season, and while it would eat electricity for the summer, that would be a fair trade-off for consistent temperature.



    Your thoughts???
  • Patchogue Phil_2
    Patchogue Phil_2 Member Posts: 303
    depends

    Depends on how much electricity costs during Summer (non-heating days).  And with the burner off during the Summer,  restart in the Fall may not be smooth.  Humidity can rust the electrode rods,  and corrode other internals.  Your mileage may vary of course.



    With an electric water heater as "storage" after the tankless coil,  the electric elements may not come on at all to maintain a setting of 125*.   With boiler coil temps higher,  only under extreme hot water use might the elements kick on.





    Also,  depending on your aquastat,  a LOW of 140 might be too low.  The low-temp trigger if often 10* less than your LOW setting before the burner gets kicked on.  130*  could be too low and you get a lot of soot.  Better minds here can answer that to more certainty.  A LOW setting of 150* might be a better alternative.



    Your ball valve as mixing valve is only good for a single temperature of the hot water coming out of the coil.  Hence the fluctuation.  When the coil temp drops,  so does your "net" hot water temp at the fixture.  A quality thermostatic mixing valve "should" give more consistent hot temps.
  • icesailor
    icesailor Member Posts: 7,265
    Issues:

    That may work for you. I've never seen it work out as hoped for anyone else but you might be the one.

    What is your obsession with not allowing -5 gallons of water to be heated in a pressure vessel, designed to extract  vast amount of heat energy out of the cheapest fuel per BTU? And swap swap it for the opportunity to heat water water with the most expensive way ever devised by man. To take a heating coil, and stick it inside a pressure vessel and use the liquid in the vessel to keep it from melting? Do you have a electric panel in this old house that can take another 30 amp 240 volt double pole breaker".  

    In the 70's I built a 5 bedroom cape and there were six of us, four teenagers. 4 zones of forced hot water heat with a tankless and a storage tank. I burned 700 to 800 gallons of oil per year. In an area where 0 degrees is used. I've had similar results with every home I have built. And no matter how much I tried to come up with a way to save money, nothing was ever cheaper than this.

    But, that electric may work for you. I've just never seen it work for anyone else.
  • NRT_Rob
    NRT_Rob Member Posts: 1,013
    not sure what you're saying

    outdoor reset doesn't help domestic hot water production efficiency at all.



    post purge would, however. that's what the system 2000 in the comparison is doing. many outdoor reset controls have a post purge feature as well, which would definitely help the efficiency in an indirect situation, but still you can't purge the boiler down to very close to indirect temp, so you'll still have significant wasted heat in a high mass boiler with an indirect for any domestic demand that is not occurring during a heating demand period.
    Rob Brown
    Designer for Rockport Mechanical
    in beautiful Rockport Maine.
  • NRT_Rob
    NRT_Rob Member Posts: 1,013
    sorry

    I just realized I didn't specify that I was only talking about DHW in my original post.
    Rob Brown
    Designer for Rockport Mechanical
    in beautiful Rockport Maine.
  • icesailor
    icesailor Member Posts: 7,265
    "Issues"

    Bob,

    In my 3 to 5 bedroom Cape with 5 zones of FHW baseboard heat and a tankless W/storage tank, I have set back thermostats that set back twice per day. They set back to 50 degrees at night and go up to 68 twice per day. I get up at 4:30 AM. At 4:00 AM, three zones come on. When I get into the shower, the rooms are getting warm and when I get out, the bathroom is at temp or close to it. When I am done, as I walk by the one upstairs where I am, I push the set back button and it goes back to 50'. I leave for the airport at 5:30. On my way out the door, I push the other two back. At 4:30 PM, they go up again to 68. I get home between 5:30 and 6:00 PM. The house is warm when I get home. It shuts off at 9:00 PM. During that morning time, I put clothes in the washer. I dry them when I get home.

    The cost of trying to seperate this equipment to do more "efficiently" would far exceed the cost savings of operation, if any, that the perceived savings.

    With boiler priority, the boiler temperature would step up anyway. I would need to start the sequencing sooner to warm the spaces, and the only time equipment is efficient is when it is running. My boiler is fired at .85. Anything smaller and I find it isn't as efficient as it can be. So, switch to gas? Not in MY lifetime. My wife "manipulates" her thermostat the way she likes.

    I am manipulating the outside temperature with my room thermostats. You and others are manipulating the inside temperature with a thermostatic sensor that measures the outside temperature and controls the inside temperature. But you don't have the control I do because I do it directly any time I want. I raise the temperature in the space. You do it with a universal control on the boiler.

    If I am not there, and my wife was cold, and I told her she had to go in the cellar and turm some thingys to make her warm, life for me will not be pleasant when I get home.

    Being part German, I DO like technology for technologies sake. In some cases, I would spend a dollar to save a dime. Being part Scots, I will spend a dime and not spend the dollar if the costs don't weigh the benefits.

    No one has ever been able to show me that the benefits to me will outweigh the costs. I think that my way with manipulating thermostats is pretty darn green. I've tried outdoor reset in houses I built and owned in the past and it didn't pay back. In fact, a house I built in 1972, I had a seperate oil fired water heater and when it failed, I replaced it with a storage tank and put in a tankless. How fortunate I had HW oil. My oil consumption went down dramaticly.

    If I/we ran out of hot water ever, my life would have been not the same as I have known it. There is no wrath like a woman with soap in her hair, in the shower and no more hot water. "Wait a while" will never cut it. 
  • NRT_Rob
    NRT_Rob Member Posts: 1,013
    I don't really know what you're responding to

    but you're missing a major issue, which is comfort. a room with a thermostat reading 68 after a recovery period from a 50 degree setback is nowhere near as comfortable as one that was 68 the whole time.



    never mind the fact that if you can achieve an 18 degree setback at all, your house has efficiency problems in the envelope you should be addressing long before you consider outdoor reset or any other control solutions.



    in a modern home a ten degree setback should be very deep indeed, and outdoor reset will greatly improve comfort. In a leaky, inefficient home like yours, setback is more important than outdoor reset.



    but as I was talking about DHW, the fact is cast iron boilers cannot do DHW efficiently without copious amounts of insulation (like the vitola) or very good post purge controls such as several MFGs offer. In most homes with oil cast iron doing DHW, you can expect to use a tank of oil over the summer. that can be cut by 2/3rds. that's all I'm saying.
    Rob Brown
    Designer for Rockport Mechanical
    in beautiful Rockport Maine.
  • ice4life1417
    ice4life1417 Member Posts: 30
    reason

    i'm not sure with oil prices where they are that it is actually the cheapest per btu. i just moved from a home that cost me 120 dollars worth of natural gas for the worst winter month. I think the last two weeks cost me that in oil. $$ per btu my ****, prove it !!! I'd switch to natural gas in a heartbeat if they had it on my new street.



    It's amazing how important the consistency of the shower temperature is when you are trying to clean your 5 month old son, that would be the purpose of the tank. Putting in an indirect, especially if i can't cold start, seems absolutely idiotic. I'd be short cycling the boiler for 9 months out of the year.



    In case you didn't notice, i would run the hot through the coil first, so as to use the coil for primary water heating and the electric for storage. It is the summer months I would have to worry about when only the electric is on. But then the water is much warmer coming into the home (shallow well)



    I have brand new 200 amp electrical service in the home, so there's room for pretty much whatever i feel is appropriate to add to the home.



    instead of just telling me to get a good mixing valve, do you have any recommendations? I stated that the watts 70A does not work well and considered putting the watts mmv on there. thoughts? i'm also putting pressure balancing/thermostatic shower valves on both showers. Maybe overkill but i don't need any accidents when the stupid mixing valve is letting 140 degree water through.



    I still don't quite understand why the temperature can't be lowered on the boiler below 140. I read so many things about cold starting and have read so much advice saying that you can and can't with cast iron. It all seems so subjective at this point when the professionals can't agree. Can anyone give a good explanation? And, because the manufacturer said so is not a good explanation, i work with many manufacturers that recommend things for there products that have absolutely no basis and it's usually just a way for them to put restrictions on their warranties.
  • Ironman
    Ironman Member Posts: 6,890
    140 deg...

    Is the minimum water temp. that most cast iron boilers need to prevent the flue gases from condensing and producing acidic water that will rot the chimney, flue and boiler.



    Connecting an electric water heater in series with the tankless coil will not save you money, it will cost you more!



    The point that has been missed here, despite some of the bellowing to the contrary, is that outdoor reset is a proven method of substantially saving money. And you cannot incorporate reset into a boiler with a coil. It has to constantly maintain 160 - 180 deg. to heat cold water that is drawn through the coil when a faucet is opened.



    If you installed an indirect, then outdoor reset could be incorporated and the boiler would be converted to "cold start", only firing when there was a call from a thermostat or aquastat.



    As far as a good mixing valve: look at Honeywell/Sparco or Cash-Acme.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • ice4life1417
    ice4life1417 Member Posts: 30
    indirect with outdoor reset/cold start

    alright.  if i understand you correctly then you are saying an indirect with outdoor reset and the boiler set to cold start would be the best option. 



    But, cold starting would allow the temperature of the boiler to get too low for 9 months of the year when we have mild weather and little demand, especially with such low standby loss on today's water tanks.  So, wouldn't this create the same condition I'm trying to prevent by keeping my lowest boiler temp above 140?
  • icesailor
    icesailor Member Posts: 7,265
    You do not understand:

    ***i'm not sure with oil prices where they are that it is actually the cheapest per btu. i just moved from a home that cost me 120 dollars worth of natural gas for the worst winter month. I think the last two weeks cost me that in oil. $$ per btu my ****, prove it !!! I'd switch to natural gas in a heartbeat if they had it on my new street.***

    You do not understand what I am saying. Nor do I really care. But someone might read what I say and understand it.

    Natural Gas Cost:

    Take the gas bill of someone in the winter during the heating season. N Gas is priced in "Therms" or "Units". 100,000 BTU's in a hour equals a therm. Take your total gas bill. That includes every add on charge to the stated price of a therm and include ALL the monthly charges. It is substantial. Divide the total number by how many therms you used. This will give you your true cost per Therm.

    You just bought the house. It had oil. Go to the oil company that provides the oil. Ask them to do a work up on how much it used during the coldest months. If they won't do it for you, they are jerks and won't be around much longer. They should be happy to give you the information. They have computer programs that can tell you anything you want to know. Go to the gas company and ask them how much you will save by going to gas. Ahve them to guarantee it in writing. They won't.

    Where anywhere did I ever suggest that you keep the 70A mixing valve. Nowhere. You do not even understand what I have suggested. You are fixated on converting to electricity to heat your water in the warmer months. And turning off your oil. Knock yourself out. Electricity is the most inefficient way of making heat energy. Fossil Fuel power plants run around 30% efficiency on a good day. Burning #2 oil in a burner in your home running at 85% efficiency:, Well, I think you can figure that one out. Some one has to pay for that lack of efficiency, transmission line loss, leaking underground loss, loss, loss, loss everywhere. And those hot shot "investors:, the "Chosen Ones" in our society. They need their cut. EVERYONE gets a cut off of our a$$es

    All the drawings for storage tanks show "pre-heating" the water somehow. I've not done that in years. It never worked. It didn't work then, and it hasn't yet now. And I never suggested it to you.

    Plumbing:

    Take that shower valve you want to "rip out" and use a pressure balance-thermostatic valve. They are very expensive.VERY expensive. If they break, the repair parts are expensive. A customer recently had a broken T-PB shower valve. It was in a custom tile shower. The valve had to be replaced, no parts were available anymore. The valve was 15 years old. No company in the world made a valve with on/off, flow control mounted on the valve. All are separate. A valve that would required cutting out the 12"X12" sandstone tile was over  $1400 just for the valve, not including trim. That's additional. I told him that I thought I could replace the valve using the same hole and using a plate that would cover the unusual shape of the hole for the old valve. He liked his T-PB valve because he could set it where he wanted it. Being brief, I told him that I have used Symmons for over 40 years. That my Symmons S96-1 shower valves all have a limit stop that must be adjusted to. That when I want to get in the shower, I turn it on to the stop, back it off a few degrees, and it is perfect for me. The water is adjusted if needed by a minor adjustment. He wanted a lot of water. I told him that if he didn't like the valve, we could rip down the whole wall and try to match the tile. Like they tried to do with the improperly installed shower pan that leaked through the ceiling. That I would give him credit for the valve if he didn't like it. I used a Symmons "Water Dance" high flow valve connected to the old stuff through a hole I cut in the sheet rock, in the bathroom. The guy was thrilled with the performance of the $400 Pressure Balance valve. Running off a 80 gallon electric, set at 130' by others.

    Oh yeah, here's another secret. If you use thermostatic mixing shower valves, you MUST have at least 130' (140' is better) on the hot water inlet otherwise, there is too much cold to control the low hot temperature. 

    Oh yeah, another secret. Electric water heaters of ANY size, with two 4500 watt elements recover 18 gallons per hour, regardless of the size of the tank and how many elements. Only one runs at a time.

    That "expensive" POS tank-less you seem to obsessed with eliminating will be delivering on a bad day, 2 GPM or 120 gallons per hour of hot water. If you use a electric hot water heater, you are slowly "storing" hot water at 18 GPH. With what "I" do, I slowly store 120 GPH. In a 50 gal WH, I recover in less than a 1/2 hour. You will recover in more than 3.

    If you are married, or married with teenagers with long hair, and you run out of hotwater, life as you know it will not be pleasant. Maybe some are used to that. I'm not. I can take two showers at the same time. I take a shower often when my wife is also. If the water got cold, my life would be miserable. I'm not miserable for that reason. No amount of penny pinching can justify that. IMHO.

    If you are going to count beans, be sure that you know the difference in the kind of beans that you are counting. 

      
  • NRT_Rob
    NRT_Rob Member Posts: 1,013
    wow

    I have no idea who you are but, a few things:



    1. If you have natural gas available, I've never seen oil beat its price. Natural gas is almost always the CLEAR operating cost winner in any area it is available. There is a reason oil is almost exclusively used in the northeast, where very few of us have access to natural gas.



    2. Oil is nowhere near 85% efficient when doing summer DHW. See previous study I have posted. More like 35%. Very few exceptions to that situation exist. Getting a gas or electric water heater can improve that significantly. Since they aren't, you know, burning home heating oil to make electricity, the economics may even work out well.



    Recovery is an issue with electric tanks. Proper sizing is a good idea in all systems.
    Rob Brown
    Designer for Rockport Mechanical
    in beautiful Rockport Maine.
  • icesailor
    icesailor Member Posts: 7,265
    Issues:

    Then why do you see when available, commercial applications using natural gas or oil and not electric for water heating?

    Out in the "sticks, motels always have electric heat pumps to provide heating and cooling climate control in the rooms. Usually LP for DHW.

    Put in a 1000 amp 3 phase service and you can heat a lot of water for not cheap.

    You miss my points. Maybe I don't make points. It's all about spending a dollar to save a dime. How long if ever, does the saving the dime take to recover the dollar. If ever in a lifetime? If the average time spent owning a home in this country is 5 years, is it worth the investment? That you will not recoup in the sale?

    Every house I ever built that I lived in, I sold it for more than I had in to it. But my sweat equity was my profit. I couldn't have afforded to build it if I hadn't built it all my self. And my wife. But even if I had hired it all done like my last house, I couldn't sell it for what it would cost me to replace it as is. But I still woould have made a profit. But I couldn't have replaced it, as is, with my profit.

    In 2000, we bought a 2001 BMW 325 XI wagon for $32,000. It came with free service for three years. It got more than the advertized MPG on the sticker. It gets 28 MPG on the highway and 24 MPG around town. It has 122,000 miles on it. It gets the 28MPG with a ton of crap in it driving to florida. The most important feature on it is cruis control so you don't go over the speed limit when you aren't paying attention. Mat it at 70 and you are doing 90 in an instant.

    I could have bought a Ford Explorer that doesn't have auto all whell drive and traction control for maybe $44,000. Gets 10 MPG around town on a good day and hopefully, 12 MPG on the highway. I don't see a lot of them on the highway on long trips.  

    What was the better deal.
  • Ironman
    Ironman Member Posts: 6,890
    Cold Start

    Cold start does not mean that the boiler will remain "cold" when it fires. It only means that it's that way when it starts. If piped and controlled properly, it will quickly reach minimum operating temp and condensation and thermal shock will not be issues. The burner will need to be set up and adjusted properly as there is a slight decrease in burner efficiency when it first starts due to the boiler being "cold".



    The outdoor reset curve would need to be adjusted to maintain 140 deg base line, but you would only be maintaining this while there is a heating call, not continuously like you're doing now.



    Another option depending on how the system is piped is to put the reset on the system loop which would allow even lower water temps in the radiation and better comfort in the house.



    The indirect would have its own aquastat controlling the temp in it and would only turn the boiler and circulator on when the tank needs heat, just like a conventional water heater does. A call for heat from the indirect would override the reset curve and provide full boiler capacity to heat the water in the tank. Depending on what temp that you set the the tank, you may not need a mixing valve, though it would be highly recommended to have it and keep the tank temp at 140 deg or above to prevent legionella.



    Look Again at what Al said in his post: He saved 50% doing this which is not uncommon. Your savings may or may not be that much, but they will be substantial and the comfort level in your house will be increased.



    Make sure you choose a good installer as the best system can be defeated by incompetency.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • NRT_Rob
    NRT_Rob Member Posts: 1,013
    easy

    for oil, they use it for the same reason many of us have been. We assumed an 85% efficient boiler would be 85% efficient for DHW. It's not, unless it's during the heating season and the "waste heat" is used to heat the house, or it's purged into the tank when you're done.



    for gas, gas is almost always cheaper than electricity. as long as you have gas. If you have to ADD gas because you were running oil before, then simply using electricity in the summer MAY make sense. I don't know about you, but generally here in maine if you have an oil boiler for domestic you can expect to go through a 200 gallon tank of oil over a summer for DHW... and people don't use NEARLY that much hot water.



    If you think you'd have a $600 electric bill over a summer with an electric hot water heater, well, I don't know what to tell you. Seems a bit steep to me. if you 55 incoming water and use 30 gallons a day, your domestic hot water bill with 0.25/kwh electricity is about a buck a day. Most of us pay less than that per kwh.



    but I'm not saying don't use gas. Use gas, if it's economical to do so, and if you have access to city gas it probably will be. but the only reason to ever use OIL is usually "I don't have gas".



    I have no idea what points you are really trying to make with your MPG and such, but let me put it this way. Let's say you have an oil boiler with an indirect, right now. You could save the cost of an electric tank water heater IN ONE SUMMER by turning off the oil boiler in april and turning it back on again in october and using electricity for your DHW. How is that for return on investment?
    Rob Brown
    Designer for Rockport Mechanical
    in beautiful Rockport Maine.
  • icesailor
    icesailor Member Posts: 7,265
    Wow/ Issues:

    This is geting way out of control here. I'm sorry.

    Someone comes here and asks "Professionals" their opinion of what to do with what they have and solutions to their problems.

    The property he now owns is the thing I deal with regularly. So do many others.

    We.re not supposed to discuss pricing here and I am not in any way, suggesting pricing. In MY world, this is a simple problem with simple solutions. I know that folks know how much they want to spend. It isn't something they tell you up front. Intuition gives some of us an idea of what that may be. Some of us do not like to give "Air Prices", prices picked out of the air. If someone has decided to spend up to $5000 to do something, and someone who is qualified and says that they will do "This" but not "that" because they can get along without that but can do this and it will be really nice for $3000, and "others" suggest prices over that magic number, guess who may get the job. And the next one. Repeat customers are my bread and butter. At 67 years old, I depend on them.  

    This is a 1800 CT New England farm house. My neck gets hot just thinking about working in it. "75% of the walls covered with baseboard". Probably over radiated.  How many feet"?  Wall to wall baseboard with sections connected through wall partitions because you can't get around underneath from the racoon poo and dehydrated dead rodents. I forgot the spiders. I need my crawlers and a good corn broom to get them out of the way. Stone foundation with lots of holes for infiltration. Boiler in a root cellar under the old kitchen. How excited I would have been to drop that WTGO in there. I work alone. How many unskilled laborers would it take to get the boiler in there without the floors buckling? If not there, in a room in a new addition. So they didn't have to work through the house and still get to that nasty crawl space.

    I told you how to solve the simple problems you have with simple solutions. You should have come here and said you wanted to do a gut re-hab and money was no object. Where I work, the designers/archetects would have turned this into a full blown fluster kluck. Raise the house, put a poured foundation under it. New direct Veismann direct vent LP with air handlers. AC and heating with flex duct and a outlet in every room with one return in a hall somewhere. All new plumbing, etc. The full nine yards. Like on "This Old House".

    You had a domestic hot water problem and an apparant shower valve problem. You have a Watts 70A that needs replacing and nothing is wrong with your shower valve if the 70A solves the hot water problem. If it doesn't that shower valve has a simple fix.

    How things can evolve.

    From a simple service call by a competent plumber to a gut rehab. Or at least a major bathroom replacement.  
  • Jean-David Beyer
    Jean-David Beyer Member Posts: 2,666
    your true cost per Therm

    "Take your total gas bill. That includes every add on charge to the

    stated price of a therm and include ALL the monthly charges. It is

    substantial. Divide the total number by how many therms you used. This

    will give you your true cost per Therm."



    January 2010 (coldest month: most therms used):



    111.67 therms used (heat and hot water; water very little)

    Basic Gas Service     $89.77

    Delivery                     $55.04

    Rebate; rate reduction $18.39-

    Customer charge         $ 8.25

    Total: $134.67



    $1.2060/therm



    Similarly for February $1.1456/therm (no rebate that month, less gas used.)
  • icesailor
    icesailor Member Posts: 7,265
    "Issues

    Rob,

    *** I don't know about you, but generally here in Maine if you have an oil boiler for domestic you can expect to go through a 200 gallon tank of oil over a summer for DHW... and people don't use NEARLY that much hot water.***



    I use 100+ gallons per summer from June to into September. And people use FAR more hot water than you imagine.

    ***for gas, gas is almost always cheaper than electricity.***

    I've never seen electricity cheaper unless you live in the TVA or Washington State area.

    ***If you think you'd have a $600 electric bill over a summer with an electric hot water heater, well, I don't know what to tell you. Seems a bit steep to me. if you 55 incoming water and use 30 gallons a day, your domestic hot water bill with 0.25/kwh electricity is about a buck a day. Most of us pay less than that per kWh.***

    $600 is HUGE. But over the years, I've never seen my electric bill go down by much, no matter what I did. And any savings comes right off the cheapest part of the bill. I've crunched the numbers over and over and I have never seen a payback Ever. When I built my new house in 2000, I could have done anything I wanted. Through years of experience, I chose what I did as my best alternative.

    We have horses. I'd burn horse $hit if I thought I could save money and it would be worth while. I've seen folks in the past, put in high tech wood stoves as primary heat with no back up. Then, when they went away for a weekend, had to hire someone to sit their house to save their expensive plants. I see a lot of expensive stoves for sale. I have a friend who creaks when he walks. He burned wood. Then switched to coal but his wife griped so much about the ash. And being hot in one place and cold in the bedrooms. He finally went to full oil FHW and is done with it. And admits that he wouldn't have it any other way.

    Also, did you do my true cost per KWH hour exercise? What is your true cost? I'm curious. Where I work, they once advertised electricity for electric heat/largeuserse a $.015 per KWH but the true costs was well over $.15 Per KWH. That is why I could never make the math work. Now, maybe it does with "Fuzzy Math".

    ***I have no idea what points you are really trying to make with your MPG and such, but let me put it this way. Let's say you have an oil boiler with an indirect, right now.***

    He doesn't have a indirect right now. That was my point in the beginning of all this. He doesn't have anything. Just a tank-less coil. With a probable broken Watts #70A. Fix that and the questions are moot.

    *** You could save the cost of an electric tank water heater IN ONE SUMMER by turning off the oil boiler in April and turning it back on again in October and using electricity for your DHW. How is that for return on investment?***

    You will NEVER save enough money to justify installing a electric hot water heater to save  money in the summer. And buying the electric hot water heater, which he does not have, will sit by idly all winter? He goes back to the tank-less?  Why do that when you have a indirect heating the water.

    But for the sake of this discussion, have him install this electric water heater and use it exclusively for ayear/season. Then, I will convert it to a indirect using the tank-less in the electric water heater. And the cost of doing that, compared to a dedicated indirect like a boiler mate or super stor. Then, we will compare KWH's and gallons. We will see who is correct. I've done this many, many times.

    Dedicated indirects are fine with me  new installs. I don't care which is used.

    What is it that you do not understand about a "Tank-less" is an indirect. The location of the coil in relationship to the boiler water is the only thing that changes.

    You are agreeing with my point. Just not what you save with electricity. If electricity is so cheap, why are we doing all these electric heat conversions? I care not what I install. Just don't waste money. You need to look at it more globally.
  • NRT_Rob
    NRT_Rob Member Posts: 1,013
    well

    I would not be surprised how much hot water people use. I do this for a living, dontcha know. the fact is it's dwarfed by heating demands in a cold climate. Maybe you are beating the curve in the summer, but a "tank of oil over the summer" is pretty commonplace with cast iron, and no reasonable estimate for MOST homes comes anywhere close to that for actual usage.



    My true cost of electricity per KWH... and I pay a premium for green electricity... here in maine is about 0.18/kwh with taxes and delivery. could round to 0.20 if you like. Fairly high nationally but not as high as some major population centers, where natural gas would of course make a lot more sense.



    boiler with a tankless coil has the same efficiency problems a boiler with an indirect has, basically, if you read the study I looked at. as long as his boiler won't leak and die if he turns it off, he'd be better off abandoning the coil for DHW except in the winter when he's heating anyway. Granted his problem also includes a badly balanced flow through his tempering valve.



    Your misunderstandings and red herrings are growing pretty tiring. We don't heat with electricity because electricity is expensive per BTU. However, for DHW, when you compare your 35% efficient oil boiler to it in the summer, the COMPARISON NO LONGER HOLDS because of the efficiency differential. At best, in some circumstances you might have the same operating costs. But only when oil prices are relatively low and electricity fairly high. This has been the case in maine for the last year or two, admittedly. But we're pushing $3/gallon for oil again and as the recession ends I hope you're not banking on oil staying where it's at.



    If you can put in a gas water heater cheaply, you'll be even better off as long as it's not propane, of course.
    Rob Brown
    Designer for Rockport Mechanical
    in beautiful Rockport Maine.
  • ice4life1417
    ice4life1417 Member Posts: 30
    now we're...

    really getting somewhere. 

     Thank you to everyone who has replied.

    Maybe i didn't communicate quite enough in the initial details as one person already pointed out.

    *

    I already replaced the guts of the 70A mixing valve, no difference. Exact same result.

    *

    The home has a full, partially finished walk-out basement (poured foundation).  There is a 3 flue chimney (whatever the lingo is for that) for a fireplace in the basement, wood stove on the first floor, and the oil boiler.  All walls insulated with fiberglass.  Older windows ( project for later) with storm windows.

    *

    I am in fact redoing the plumbing in the home, gutting both bathrooms and the kitchen so I'm renovating all of the water systems since there were "issues" as reported by the previous owner and verified by inspection.  Moving to a homerun pex system. 

    *

    I am not deadset on getting the electric, I just believe i have a lot of waste and inconsistency at the moment and it appears to be the best, safest option.  I'm not sure that I mentioned it, but my boiler is 25 feet away from the nearest faucet (stupid placement i assume because it was easier to vent through the chimney) It being the begining of the heating season, it's not moving anytime soon.  So it also takes forever to get hot water at anything low flow.

    *

    If a quality mixing valve would fix my child safety problem then I would be ecstatic.  I don't want to be a worry wort but i have the ability to act before something happens and while i have everything open so now is the time for me to make the move.

    *

    :( I don't have the ability to get gas.

    *

    Feeding an indirect would solve the fluctuation issue, i agree.  But i still don't see the feasability for summer heating unless i were to cold start.  And as a secondary issue, the time to hot water at the faucet would be the same because i would have to place the indirect near the boiler, right?

    *

    Cold starting - help me clarify, it's OK to cold start so long as it fires to over 140 boiler temp every time it does fire, doesn't matter how far it cools after that between fires?  It is only dangerous if I am consistently maintaining a temp under 140 even when it fires.

    I really do like the idea of an outdoor reset. Although (pretend the water is of no consideration for this question) could I set the low limit of the aquastat to 115 with a differential of 25 and a high limit of 170-180.  Then the boiler would always fire to 140 from 105 and continue heating to about 150 with the radiation of the cast iron after the burn.  And it would fire to HL when there's a call for heat. Would that option be cast iron approved? Or something similar to this in the meantime before i can get to the reset.

    *

    If i didn't care about waste, I would scrap this entire system and start from the ground up with a complete redesign.  BUT, this system is only 4 -5 years old and i really would feel like a complete jerk if i scrapped it.  I want to maximize it's efficiency, effectiveness and safety.



    I understand that the electric would cost me a little extra in the winter because it would have to maintain additional capacity and i hate thinking of using electric for any heating application.  BUT, safety and comfort are my primary concerns, Then efficiency is a close third, but third nonetheless. 

    The main reason i wanted to run through the coil is because i believe 100% that heating the water from 40 degrees to 120 in the winter will be done more efficiently by the boiler. I think everyone would agree with that.  the tank would solely be for maintaining.

    I also don't really want to have to keep my boiler at 160 180 to maintain 130+ temperatures in the house. I'd rather keep it cooler and burn less oil on the regular while pumping 110-120 degree water into a seperate tank.

    I am also in the process of insulating about 60 feet of exposed copper heating pipe in the basement.  No need for that !!! 

    *
  • icesailor
    icesailor Member Posts: 7,265
    Issues: Last Post

    #70A Watts:

    I have NEVER replaced the guts of a 70A and been successful. Only replacing the whole valve. That's why I started converting to storage tanks. On "good" jobs, I install a thermostatic mixer on the outlet of the storage tank. Even on electric only that are small for the application so I can run the water hotter and store more usable hot water.  So I can run hotter water but maintain even temperatures.

    Did you ever hear of hot water recirculation? It works great. It just costs money and saves a lot too. Just a pump.

    Massachusetts was the first state in the country to require "single lever pressure balance valves that open in the cold position with a limit stop to limit the amount of hot water entering the shower head."  Any device that will allow water to be sprayed on to a body must first go through said valve. Symmons was the first to develop this valve for use in school and public showers. Repair spool assemblies are available for valves made in the 1950's. If you are afraid that this valve will not protect you and your children from scalding, you are paranoid. I asked you what kind of valve you have. Is it single lever? What brand and model? What model? With a symmons, you can not turn on the valve in the hot position. If the limit stop is set to control hot water, you can not turn the valve too hot. If it is a symmons, and the handle points to 12 O'Clock, and you turn the handle counterclockwise, and the valve doesn't stop when pointing to between 2 O'Clock and 1 O'Clock, the valve was never "set" by the installer when installed as per instructions from the manufacturer. And current code in Massachusetts and probably in CT.

    A indirect or storage tank with a quality thermostatic mixer will solve all your temperature fluctuations.

    It doesn't matter what temperature you run your boiler at. There is nothing dangerous about it. But, there is water vapor in combustion. Boiler water temps. below 140 cause the water vapor to condense on the boiler surfaces. Ash and other crap in the flue gasses stick to it. It makes a mess, insulating the boiler from the heat. A clean boiler run above 140 will stay clean and efficient. It's that simple. A Indirect will make the boiler run hot until satisfied. It's getting there to hot that is the problem. If you use indoor/outdoor reset, the boiler will run cold on cool days. How many feet of radiation do you have? A storage tank allows you to drop the operating control (Low) to 140/145. The high to 160/165. That will heat your house maybe always and give you all the hot water you will ever need. And heat downsize the radiation in your house because of less output. With a indirect, and outdoor reset, you need a complicated thermostatic mixer to keep the boiler water hot so it can add hot water to the water in the heating loops.

    I wouldn't scrap a thing. Unless you want to spend a ton of cash and you don't sound like you do.

    Do you not understand that I have never said anything about using electric energy to heat water? Not ever? I suggest using a electric water heater because it is the cheapest insulated hot water tank that you can buy. By far. You DO NOT use electricity to heat the water, The only electricity used is to power a small electric pump. Operated by a thermostat that is prewired in the electric water heater. IT DOESN'T HEAT THE WATER!!!! It only pumps the water through the indirect coil in the boiler called a "Tankless". Like the circulator that pumps boiler water through the coil in your INDIRECT water heater.  THE ONLY DIFFERENCE IS THE LOCATION OF THE COIL. COMPRENDE? You could use a 40 gallon or a thirty. A twenty. It's just a insulated tank.

    End of discussion.
  • rlaggren
    rlaggren Member Posts: 160
    Icesailor hit the nail

    If you deal with the fluctuating DHW, you've made a major improvement at a base cost. There is no reason your existing system can't supply good steady hot water; a tank would provide a cushion and a reserve but the system should work just the way it's set up provided it's parts are good. To really eliminate any question, you could hook up a pressure gauge a couple places and make sure your supply pressures aren't doing anything funny prior to the boiler or the tempering valve.



    As a plumber I _know_ hot water is one of those hot button issues for a family. You fix that and life will all of a sudden be looking way better. Then you can actually enjoy planning any other improvements.



    Rufus
    disclaimer - I'm a plumber, not a heating pro.
  • icesailor
    icesailor Member Posts: 7,265
    Fluctuations:

    Ice,

    I wasn't going to reply to this anymore but,

    You live in the sticks of CT. Do you have a private water system (well)? If you do, what are the pressure settings?

    If you are on a public water system, and you are up high and your incoming pressure is under 40#, you will have pressure problems on the second floor. A 70A will cause excessive restriction causing pressure balance shower valve to adjust to the lowest pressure giving unsatisfactory performance in the valve. If this is your case, you need a booster pump system.

    If you have a private water system (well), what is the cut-in/cut-out pressure?

    20#-40# will be unsatisfactory. 30#/50# is acceptable. 40#/60# is optimum.

    If the water tank is in the cellar, and the gauge reads whatever it reads, remember, 1' in elevation equals .434 PSI Guage in altitude. I round it up to sat, 10' per floor. 10' each for the cellar and first floor. 5' added for the second floor for the shower valve and head. Equals 25' elevation divided by two (2) equals 12# PSI Guage on the second floor. A second floor shower will never give you the pressure that a first floor one will. Hence,low pressure in a pressure balance shower valve will be affected by low pressure.

    Mechanical problems require  golbal and world view of the interactions of plumbing and HVAC systems.

    I'm also a MA licensed well driller and install water systems.
  • ice4life1417
    ice4life1417 Member Posts: 30
    well

    I am on a well set 40/60.  I have verified the settings are correct and recently pumped the wellxtrol.   I do not have a pressure balancing valve upstairs yet.  It's just a really old three valve.  Actual water pressure at the second floor seems to be fine, except the dreaded sink which i think is crudded up.

    *

    I think the pressure issue is at the mixing valve after the coil.  where the cold water is still at full pressure and the hot water going into the mixing valve is lower because of pressure loss inside the tankless coil.  I have read there should be a pressure regulator on the cold side before the mixing valve to account for this drop.  But, if I understand correctly, the pressure regulator will always limit the pressure to one fixed pressure.  That would be great for more consistent city water lines.  I have a variable pressure system so a pressure regulator wouldn't really do me any good.  Right?  Cuz then (let's say i regulated the cold to 45 psi) the hot water pressure would fluctuate between 35 and 55, still unbalanced (assuming 5psi drop in the coil).  ***What if I set the cut in/out to 50/70, put a pressure regulator on the main trunk at 50, then a pressure regulator before the mixing valve at 45 to account for the pressure drop through the coil???? would that solve the pressure balance issue to the mixing valve.

    *

    Do mixing valves require a specific input temperature? 
  • Jean-David Beyer
    Jean-David Beyer Member Posts: 2,666
    Do mixing valves require a specific input temperature?

    I do nto know about all mixing valves, but my 2-stage Lawlor valve requires the hot to be at least 15F hotter than the hottest you want to get from the valve. They do not say, but I imagine the cold should be 15F colder than the coldest you want from the valve as well. I know in the summer when the cold water is pretty warm, I cannot get the output down to 75F some days, but I do not remember what the cold water temperature is then.
  • icesailor
    icesailor Member Posts: 7,265
    Issues:

    Three valve shower/tub fillers are a no-no. I would not let my child, wife, myself or anyone I cared about  take a shower with one.

    If you are planning to put off renovations for a while, but do some things, I would attend to this shower valve as one of the first things. I don't know the condition of the wall that the valve is on but if it is OK, Symmons makes two plates that are designed to be used when replacing a three handle valve with one of their valves, a S96-1 or 2. You would use a S96-2 because that is for a tub and shower. This is the plate I used to replace the shower valve in the house I mentioned earlier. It is designed to not rip open the wall. And when you cut out the wall so that the plate will cover the hole, you can replace the valve from outside and nothing shows. It is a easy job for a competent installer. Competent is the key.

    So, getting back to the (tankless) indirect coil. The valve mentioned does not "regulate" the flow as much as it restricts the flow. It is supposed to keep the flow constant so the tempeature doesn't fluctuate. I've never seen them work as advertized except for the time I installed a iron removal system in a house that needed the irrigation water treated because wherever the water hit, whatever was white turned rust brown. The trim paint, the flag pole, the white shell driveway where the water hit. I told the irrigation guy that  he had 7 GPM's and 2000 gallons of water before it would regenerate. Change the zones and heads to reflect this. He was smart and I wasn't. I was the a$$hat and he wasn't. The house was painted, the flagpole was painted, new shells were put in the driveway and the treated water stained the above.I checked he head flow on the zones. One zone was 15 GPM. On a 12 GPM submersible. I installed a 5 GPM flow restricter and that fixed his butt. See, it restricts the flow. The pressure stays up if you don't try to exceed the flow.

    That's why indirects and storage tanks work well. You will always have qual pressure on both the hot and cold. There can be all the pressure drop in the world through the coil but it doesn't matter. Whether the circulator is pushing the water through the coil at 1 GPM or 5 GPM. It doesn't matter. It just keeps on ticking. Like the energizer bunny.

    You don't have a continuous pressure set up on your well do you? I distrust them intensly.

    Also, if you install a Symmons valve, you can always use it over. It is a solid brass valve, made in the USA (not China) in Braintree, MA

    You do not need any fancy stuff to do what you want. Unless you want to spend a lot od $$$ on your projects, keep it simple.

    There's ice in Maine. It's moving South.
  • icesailor
    icesailor Member Posts: 7,265
    Lawler "Issues"

    JDB,

    I mentioned here about theromstatic valves. That is the thing about them that I mentioned. You need a temperature differential between the hot and cold. The greater the differential, the better the valve works.

    The cold water will not usually ever get below 55 degrees. Those valves work very well for what they are designed to do.
  • ice4life1417
    ice4life1417 Member Posts: 30
    thanks

    Once i get my shower on the first floor up and running I'll reassess. Maybe having a good solid valve on there will make a huge difference. Unfortunately I won't know for a few weeks when the bathroom is completely finished.

    *

    Anyway, thank you all for your help.
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