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High delta T, how to adjust it?

135

Comments

  • Mark Eatherton
    Mark Eatherton Member Posts: 5,852
    Caution...

    Laser IR non surface contact thermometers are NOT accurate on shiny copper pipes, and can give you ALL kinds of erroneous numbers. Dull the surface being sensed with teflon paste, or duct tape before reading. Otherwise, you're spitting in the wind. Once you have solid numbers, then fall back and diagnose. You're headed in the right direction (logically) just make sure the readings you are getting are correct and not false. A thermistor in contact with the surface is much more accurate and not dependent upon the materials emissivity for accuracy.



    Pay no attention to the man behind the curtain... (Oz)



    I am in agreeance with everyone else, in that there are no less than millions of homes like yours with THAT exact same pump and they work just fine. You could have an impeller partially chewed up by solder ball or some other "thing" in the system.



    Once you figure it out, you're going to slap yourself on the head and say "DOH" It's probably a lot simpler than you thought.



    ME

    There was an error rendering this rich post.

  • Tom_133
    Tom_133 Member Posts: 904
    Pics...

    Earl



    I think we need more pics of the current setup. I have a hunch but need photos to offer it, I don't want to look like a simpleton.
    Tom
    Montpelier Vt
  • NRT_Rob
    NRT_Rob Member Posts: 1,013
    gee

    tom why not? the rest of us are happy to look dumb ;)
    Rob Brown
    Designer for Rockport Mechanical
    in beautiful Rockport Maine.
  • Earl
    Earl Member Posts: 85
    Yes, copper hates laser IR

    Yes, I found out quickly that the laser IR doesn't like copper. I looked online and found like you said, use tape, marker, paint and etc to get better readings. Also I use my contact K thermocouple on my meter.



    Not sure why some are fully against me measuring my system and seeing if the 007 is ok for my system? It's easy, free only requireds a tape measure and some math. Some even say they've seen more piping on other systems but how do they know what my piping looks like? I don't even have a clue how many feet of pipe I have not alone 90's and 45's and such.



    I also agree it has to be something simple. Never did say it was some curse or such. lol It's either a blockage, bad/damaged circ or wrong size circ. Some ppl on here argree and some don't. Even one guy says its all in my head that the system is fine. But yet I have poor uneven heat. Guess his knows my house better than I, maybe? Who knows. Figured the simple thing to do first is make sure the circ is sized correct and go from there. I'm not lazy, I don't mind measuring pipe and counting fittings and doing some math. If the 007 is the pump for the job, than I will remove it and look at the impeller. I'd rather do the pump sizing first as it's easier than trying to remove rusted bolts and hoping the flange O-rings can be reused. Probably break off the bolts and have to go get some, etc. Not my idea of fun unless I really have to pull it. lol



    Earl
  • NRT_Rob
    NRT_Rob Member Posts: 1,013
    earl

    there is no way the pump is undersized. I don't care how many 90's you have. if you measure it all and find that the pump is undersized, you're wrong. it's that simple.



    your problem is not circ sizing. say it with me now! your problems is NOT pump sizing. it may be a bad pump, but it's not the model number causing your problem.



    to get this pump down to, say, 5 GPM (where it would have to be to even run a 50 degree dt for any length of time with your boiler) you'd have to have about 10 feet of head. If your flow rate were REALLY that low, split through 2 circuits, you'd have about 1.5 feet of head in the baseboard. I don't care how many elbows you throw at it, and I don't even care what model boiler you have... you don't have 8 feet of head on top of the baseboard here at 5 GPM unless you've got something really, really weird here like a 1/2" return crossing the house or a hundred foot 3/4" combined return or something.



    so this pump should be pushing significantly more flow, with a lower delta T. period. finding out why it's not is a good exercise. trying to confirm this pump is appropriate is, in all likelihood, a waste of time and energy.



    but if it makes you feel better, knock yourself out.
    Rob Brown
    Designer for Rockport Mechanical
    in beautiful Rockport Maine.
  • Ironman
    Ironman Member Posts: 7,441
    Rusted Bolts? Bad O Rings?

    You don't take the flange bolts off to look at the impeller. You take out the 4 screws that hold the motor casing to the pump housing. All it takes is a 5/16 nut driver.



    If the flange bolts are rusted to the point that you're describing, then you have a leak that needs to be repaired and that could be causing a number of issues.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • NRT_Rob
    NRT_Rob Member Posts: 1,013
    good eye bob.

    didn't even think about the rust.
    Rob Brown
    Designer for Rockport Mechanical
    in beautiful Rockport Maine.
  • Mark Eatherton
    Mark Eatherton Member Posts: 5,852
    Regarding bypass...

    Yours is a rarety. Most (like 98%) of them don't have one, and of those that do have them, the bypass is completely closed, and its not a problem,



    For giggles, try closing off the bypass. And see what happens to the flow.





    I've seen a lot worse (snow melt applications with NO bypass) and the boilers are still clicking and ticking.



    ME

    There was an error rendering this rich post.

  • Earl
    Earl Member Posts: 85
    Pics

    Pics of at boiler piping. Cut off in the pip after the swingcheck is a 1X3/4X3/4 tee where it supplies the two loops. I did attach a pic of the tee. I also included a pic of the "Y" where the two loops return on a 1" back to the boiler.



    The pics were taken after I had to open the bypass. This is how the old boiler was when I installed the new one. I replaced the gate valves with ball and replaced the leaking auto air vent and added the bypass which was always closed till I adjusted the flow on the 42' loop to get heat out of the 58' loop. I also installed the new water feed regulator. The boiler has 12 PSI cold and hot. At some time the expension tank started to leak and they had someone install the air scoop, vent and bladder tank.



    Earl
  • Earl
    Earl Member Posts: 85
    Rust, Bolts and seals

    No, no leaks, just rusty from being in a damp basement since 2005. If it's metal, it will rust in my basement.



    Didn't noticed the motor comes off the housing. What seals that? O-ring? Will I have trouble with the seal? I don't have parts so if it leaks I'm screwed until I track down parts.



    Earl
  • Ironman
    Ironman Member Posts: 7,441
    Earl, Close that Bypass!

    A bypass should always be at least on pie size smaller than the mains. Water takes the path of least resistance. Which do you think would be easier: going through the bypass back to the boiler or traveling through a hundred feet of pipe?



    The return temp will rise to a proper temp after a few minutes if you get the flow going right.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • Earl
    Earl Member Posts: 85
    Bypass

    I added the bypass as per the burnham install manual. I never used it, was always closed. When I reduced flow to the 42' loop to get heat to the 58' loop, my return temp fell below 140 so I had to crack it open to protect the boiler.



    If I close the bypass return temp stays below 140 and no change in heating. If I close bypass and open the 42' loop balance valve fully, I get 160 or so return temp to the boiler but my 58' loop craps out and drops to like 90 degs return if I remember correcly. Always an issue with that 58' loop.



    Earl
  • Earl
    Earl Member Posts: 85
    Bypass

    I did close it, it changed nothing other than drop below 140 return temp to the boiler. That's why I opened it. I left it run from the time it called for heat till the t-stat kicked off, return temp stayed below 140 the entire time. Bypass was always closed till the other day. When I reduced flow to the 42' loop to push more flow into the 58', my boiler return temp dropped. So I had no choice but to open the bypass to protect the boiler.



    The bypass sizing is how burnham wanted it. Well they wanted the at boiler piping to be 1.5" but I kept the 1" that was there adding the 1" bypass. Burnham wanted the bypass 1.5" as well.



    Earl
  • Ironman
    Ironman Member Posts: 7,441
    Swing Check?

    Why is there a swing check on single zone hydronic system?



    Could it be that it's not opening properly considering that you have obvious leak issues which cause fresh make up water to be added with all the minerals it contains?
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • Earl
    Earl Member Posts: 85
    Swing Check

    It was there, so I kept it. The old boiler use to be used to heat DHW so it was probably needed then. New boiler is cold start. Wouldn't you want a swing check to stop the boiler from gravity flowing when the call for heat stopped?



    Yes, the old air vent was leaking, I replaced it with a new taco when I installed the new boiler. Also I installed a new bladder tank than. I believe it's undersized but seems to work ok. Not sure who installed the air scoop and bladder tank, I just replaced the baldder tank with the same size.



    Earl
  • Earl
    Earl Member Posts: 85
    Swing check

    I do know the swing check closes as it doesn't gravity feed. It opened and closed ok, and i washed it out and such when I installed the new boiler. But I can't say it's operating correctly as I don't really know. I know it has a manual thumb screw on top to manually open it but it's too tight for fingers so I never tried to use tools to open it.



    Earl 
  • Earl
    Earl Member Posts: 85
    Swing Check

    If I open and close the bypass quickly, the swing check will rattle. Not sure if that's an indication that's its working or not.



    Earl
  • Paul48
    Paul48 Member Posts: 4,469
    Earl

    Is that reducing tee plumbed into the supply?
  • Earl
    Earl Member Posts: 85
    reducing tee

    Yes, the reducing tee is after the swing check on the supply to each loop. It got cut out of the pic. It's probably 5 to 6 inches after the swing check. The pic of the "Y" is the return from the loops at the end of the house. Boiler is at the other end.





    Ear
  • Zman
    Zman Member Posts: 7,609
    Earl

    Earl,

    Why is that ugly black 007 still attached to your boiler? Where do you live? I am coming over to change it.

    Carl
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • jamplumb
    jamplumb Member Posts: 16
    air

    This has been a really interesting thread. But I think we are forgetting one of the things that seems to always kick our but, air. It looks like the boiler is in the basement, it would be very easy for air to keep the one zone from heating. Unfortunatley it does not look like the two zones can be purged one at a time. I dont know how many times I have spent to much time chasing other "problems" when it was air.
  • jamplumb
    jamplumb Member Posts: 16
    baseboard T

    Earl, thought of one more thing. If you are lucky maybe the original installer put baseboard t's on your baseboards. Check both ends of the baseboards under the end caps to see if there is a brass 90 with a small fitting on the top with a straight scew fitting. These are ment to let trapped air out manually. Use a good screwdriver that fitts the slot and slowly back it out half a turn at a time. It should'nt take more than two turns, be sure to maintain good control of the screw and do not back it out any further.
  • Earl
    Earl Member Posts: 85
    No bleeders

    No bleeders on the baseboard heaters. I have the air scoop vent and a manual air vent on the top of the return at the boiler. Vent on the air scoop is auto and open. Everytime I check the manual vent, there's no air. I don't have any noise but I guess an air pocket could be trapped somewhere. I would of thought any air would of been pushed out the 58' loop when I closed the balance valve (blade valve) off on the 42' loop.



    No, there's no way to purge each loop. I'm thinking about throwing ball valves in the suppy of each loop so I can close each loop off 100% for testing and purging.



    Earl
  • Earl
    Earl Member Posts: 85
    It's a fit all size

    Carl,

    Getting a lot of replies that this pump will work in any house, so it must be one size fits all pump. I don't know much about pumps other than types of pumps and some applications. Hydronic pumps I have no clue. It came on the boiler so burnham must also agree it fits all applications as well. I looked on the Taco site, they make lots of pumps but they do say the 007 is their top selling pump. So either my 007 has an issue, air trapped somewhere or some other issue on the 58' loop.



    Earl
  • Gordy
    Gordy Member Posts: 9,546
    edited January 2013
    System pressure?

    Earl, what is the pressure gauge reading?



    Have you checked the pressure in the expansion tank .....properly? That's with system at ambient, and tank isolated from the system



    I see a lot of mineral,stains on the air scoop which means its been weeping water through the vent, and your fill water supply is off. Which means over time system pressure can drop.





    Low system pressure can create flow issues. Don't trust the gauge on the boiler check the tank.





    As been said leave the bypass off.





    Where are you taking your temperature measurements? At the boiler, base board?
  • Pughie1
    Pughie1 Member Posts: 135
    If you get water it ain't an air problem

    I keep reading about an air problem here. There is a purge valve located above that ball valve above the circulator. you could close the balancer in the 42' loop to purge the 58' loop if you are familiar with the proceedure. This may be getting on the dangerous side if you're not!  Can't tell from picture where the make up water line enters the system or if it is of the "fast feed" type. There are ways to purge this system, but again it could be dangerous - Re: feeding cold water in to a hot boiler, relief valve discharge, etc. Perhaps some one may want to walk you through it.



    PS  I used some estimated numbers and ran it through my Hydronic Design Studio ( from "Siggy" as Mark said)  circuit simulator. Delta T numbers come out normal but a warning comes up when I play with my balancers. the warning indicates the circ. is approaching over 90% of its capable head on the 58' loop and to consult with the manufacture. I certianly agree with the consensious the 007 should work.
  • Paul48
    Paul48 Member Posts: 4,469
    edited January 2013
    Earl

    The math problem I ran in my previous post ,that came up with 2.8 GPM,is the Universal Hydronic Formula.Those numbers are not arbitrary. If they don't seem to match the specs on the pump curve, look for a restriction to flow, or damaged impeller. Check the(local) availability of a 007 cartridge and change it. If you're going to remove the old to inspect, you might as well replace it.



    I don't recall it being asked......Is this a mon-flow system?
  • Earl
    Earl Member Posts: 85
    Purging

    The fill regulator does have a fast fill handle. It's tee'ed into the boiler supply just before the air scoop and after the shut off, so if the bolier supply valve was closed, cold water wouldn't enter the boiler.



    Earl
  • Earl
    Earl Member Posts: 85
    System pressure

    Gordy,

    The stains are old, that vent was replaced in 2005 and doesn't leak. The bladder tank was aired to 12 psi cold with no pressure on the system. It's soild sounding on the top and hollow sounding on the bottom when I tap on it. I checked the air pressure on it this past fall.



    Pressure is 12 PSI cold and goes to just under 20 PSI at 180. Believe the bladder tank is one size too small.



    I take temp measurements at the boiler and at the balance valves.



    I keep the fill supply off in case there's a leak so nothing floods or new water is being added without my knowledge as my water is hard and I don't want crack the boiler due to hard water build up.



    So you're saying close the bypass and let the boiler return run below 140 degs?



    Earl
  • Earl
    Earl Member Posts: 85
    Mono-flow

    It's a split series loop system. Baseboard heaters are in series, one loop on the west side and one loop on the east side of the house.



    Earl
  • Earl
    Earl Member Posts: 85
    Velocity noise

    Noticed one baseboard heater on the 58' loop has velocity noise and none of the other heaters on that loop has noise. Could that be a restriction? It's the 6th heater out 8. Noise seems to be coming from the end of the heater near the riser.



    Earl
  • RobG
    RobG Member Posts: 1,850
    Start From Scratch?

    How about starting over with the near boiler piping. The Burnham piping diagrams, Tacos diagrams (and common practice) have the circulator after the air scoop and expansion tank. PUMP AWAY (from the point of no pressure change). Unless you start with the basics, air will always be your enemy. Fix what you know is wrong first, then move on from there.

    JMHO,

    Rob
  • Pughie1
    Pughie1 Member Posts: 135
    velocity noise

    Earl,  I doubt it's velocity noise, you're no where near 4 ft/sec. I bet your hearing "AIR". I'd try purging that loop thoroughly.
  • Earl
    Earl Member Posts: 85
    Doubt its air noise

    I don't agree its air. Its a roar noise and only in the one heater. Goes away when I open up the 42' loop. Air noise would be through out the loop/system I think. No gurgle, no water fall, no trickle noises. Also I can't purge the loops individualy the way its currently plumbed.





    Earl
  • Pughie1
    Pughie1 Member Posts: 135
    purging

    Earl - Sure you can - just close the 42' balancing valve and purge the 58' loop keeping preasure as clos to 30# as you can. Hook a garden hose to the purge valve and close the ball valve under neath it and run 5 or 10 gallons to a drain.Then do the same for the 42' loop, keeping the pressure as high as you can.

    Listen to these guys, they know what they are talking about!
  • Paul48
    Paul48 Member Posts: 4,469
    OK

    What's your plan of attack? The only thing everyone is close to agreeing on is....you have a circulation problem. Let us know when you've tried one of the suggestions.
  • Zman
    Zman Member Posts: 7,609
    The real question...

    Can you help me fix my system without spending any money or disassembling anything? The simple answer is no.You cannot evaluate the condition of a circulator with an ampmeter. If it is partially corroded or the impeller is worn your test is meaningless.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • Paul48
    Paul48 Member Posts: 4,469
    Yep

    We've exhausted the "What-ifs" and "Maybes. It's time to put your hands on things.Six days is plenty of time to formulate a plan of attack.
  • Earl
    Earl Member Posts: 85
    The real answer

    Never said I wouldn't spend any money. Can't fix things for free. Never said I wouldn't take anything apart, just rather not too unless I really really have to. Remember, I don't have a service truck full of parts, I take something apart and it breaks or the seal won't reseal I'm screwed and without heat. One guy asked me to check the amp draw, just trying to follow what I'm told as best I can.  
  • Tom_133
    Tom_133 Member Posts: 904
    I agree...

    I think we need a pump to find out where we are at.



    Is that triplestat the style that only kicks circ on when boiler is up to temp?
    Tom
    Montpelier Vt
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