Steam and Hydronic system not working well

Unknown

You would not want to add any more capacity to a steam boiler sized for the steam heat . So if you came up with 200 sq. ft. of heat , you want a boiler that size - unless you need to factor in the pickup . Which would be another 1/3 of your sq. ft. number . I'm not good at math , I think that makes it 266 sq. ft . So your boiler is most likey more than 2 times the size you need .

I know you don't want to hear that . The limited good news is that a properly sized and piped heat exchanger should give you plenty of heat on the hot water side - if the heat in there is properly sized .

The bad news is that a grossly oversized steam boiler will cycle very often , increase your fuel bills , and more than likely give you a whole host of steam heat problems in the piping .

Did you contact a pro to look over the system yet ?

Michael G.

sludge? steam and hydronic combined system not working well

We are having problems with the heating system in our house -- it is not heating the house adequately and hasn't done so since we moved in! This is our 3rd month in the house and the previous owners converted from an old oil system to gas just before we bought the house and we now have steam in the old part of the house and hydronic/baseboard in the newer part of the house, all being run by one new gas boiler with a heat exchanger on it.

We asked the plumber to come over today and have a look at it since we weren't getting enough heat. He said that there was sludge that had built up in the steam system from the old pipes and that it had destroyed one circulator. He claimed that he couldn't guarantee the circulator since he was not responsible for the pipes that were in the old part of the house that he had never worked on. I told him that that was not acceptable since he had told me (before I bought the house, when I asked him if it made sense to do more work and upgrade the system further at that time, and he said absolutely not!) that it was a brand new system which he was very proud of and which he told me would be more than adequate
for our home. When I asked if he could prevent/limit this from happening again (maybe flush the lines a few times?) he said that he couldn't guarantee it and that he couldn't flush the lines in a steam system (I don't understand that -- is that true? doesn't sound right to me).

He left my house before I returned from work this evening and so I didn't actually speak with him after he worked on the system today. He did however mention to my wife that we might have a more substantial problem.



Right now, we have very little heat in many of the rooms/radiators (some work and some don't, even within the same room) in the house and it is cold and I don't know why?

I have attached photos of the boiler, heat exchanger, etc. for you to look at. Please feel free to ask for more or for anything else that might help you diagnose the problem better.

Any thoughts/comments/advice for me for when I speak with him next/tomorrow?

Unknown

Michael

Can you edit your post to uncheck the box that displays the 1st pic ? This pic is so big that you have to scroll to read your whole post . Thanks .

I can see a few problems right off the bat .

The heat exchanger - do the supply and return connect to the bottom of the boiler on opposite sides ? The water might be passing right through , not picking up much heat and might not give you a high enough temp to the zones of water heat ( unless the boiler is at steam temperature , maybe .... ) . And the flat plate heat exhanger might be clogged with steam spooge . Any chance you can tell us what the temp gauge reads on the hot water side with the zones running , but with the steam zone off ? And do the same but with the boiler steaming ? Also , what is the aquastat set at on the boiler ?

Do you have a pic of the steam piping above the boiler ? Copper for the header is a no-no , but the choice of material would not affect the heat output . Undersizing the recommended boiler main would affect it . Can you give us the model number of the boiler too ?

Best way to start and sort this out is figure how much steam radiation you have and see if the boiler is the right size . If by some miracle it is the right size , you need to find out the heatloss of the hot water heat part of the home . I believe if the heatloss of the hot water side is more than 1/3 of the output of the boiler ( someone please correct me if I'm wrong ) , you will have problems on the real cold days . If the hot water side has too much radiation , it can actually keep the boiler from steaming .

Ask away if you need more info on how to work the numbers . there are far smarter people who post here and can explain it easier .

Michael G.

Ron Jr.,

Truly appreciate your input...I feel very lost here as I am a first time homeowner and am quite ignorant about heating systems -- I just want it to work and be warm!

The boiler is a Dunkirk 2.62 PVSB 8D (Con Ed put in a new Class 500 bar and Class 500 meter -- whatever those are).

Regarding your questions....

1) I am attaching a photo of the steam piping above the boiler.

2) I am not really sure if the heat exchanger connect on different sides of the boiler, but it seems that way to me. Perhaps you could tell from the photos, or if you want additional photos to help clarify, that would be possible as well, just tell me which photo # to detail further.

3) As far as the diagnostic tests (steam radiation etc.)that you suggest, I would need far more information as to how to do that. I also don't know how to turn off the steam side to get you the temperature reading.

I'll need more detailed instructions unfortunately in order to run any diagnostic tests.

Thanks,
Michael

Dana_5

Absolutely will not work. Don't let him back in your house, find a contractor in your area that knows steam and hire him to re-install. If your in the Boston area tell me how to contact you.

Michael G.

Dana,

Thanks. What won't work? What will I need to be reinstalled? What do you do for a living?

Christian Egli_2

You're half-way there and we're half to the cold season already

And for a bit of bad news

Those big copper pipes that connect the boiler to the older and nice looking cast iron pipes is a big source of problems. This needs to be corrected no matter what. Go after the installer and request near boiler piping as per the boiler manual.

The good news is, copper scrap is highly valuable.

This will solve many of your uneven steam problems.

First thing to do about the whole house problem is to measure everything with numbers and see how much steam radiation there is, how much water radiation and how big the boiler is and how much the small heat exchanger can actually transfer. At the same time, check all the venting and/or traps arrangement.

The problem of sludge build up is very believable, your current layout makes the hot water heat exchanger and pump act like a continuous by-pass filter. It would not be surprising to see the small exchanger all clogged up.

It seems you are demanding too much of the single boiler, perhaps a second hot water dedicated boiler might be the best solution. Try running the steam boiler with the hot water part turned off and shut off and see if you are improving your steaming ability. This will tell you quickly if buying a separate water boiler is in order.

Look into how you are making your domestic hot water, perhaps some improvements can be made here as well with combining the hydronic demand to it. (Personally, I prefer an appliance for each use, here three, with natural gas you don't save yourself much maintenance work by using one burner only)

Otherwise, the blue boiler looks real good and steam heat is an immense source of comfort for those lucky enough to have it. Getting you there should not be a horrendous exercise.

Good luck. Is it cold where you live?

Weezbo

i think you need to get rid of that headder.....

the copper tubing will strech and thin ...even if the manufacturer installed it i would lose the copper.

Christian, you must type with two sets of hands )

Dana_5

I actually left my office for the weekend after my last post but came back. First time I've ever done this but call me 508-479-0516. But first shut the boiler off, if he piped it this bad, who knows how its controlled or wired.

Michael G.

ok, I will change the header. what do you think it should say?

Michael G.

what should the copper piping be replaced with?

Michael G.

First of all thanks for your help and support!

1) What is wrong with the big copper pipes? Do you think that my installer had no idea what he was doing?

2) I am totally new at this and don't know what I am doing, so to do any of these diagnostic tests is a bit daunting for me. Any easy suggestions?

Ted_9

black

black pipe

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Dana_5

Again, call me, 508-479-0516. Dana

Ron Schroeder

A header should look

someting like this

http://www.heatinghelp.com/pdfs/224.pdf

jim s_2

please don`t try this

yourself.

That boiler is piped totally wrong for steam and will never work properly until the near boiler piping is corrected.

Did he leave the owner`s manual? If he did,look through it until you find the installation diagrams,if not go to dunkirk`s web site and download the instructions from there.

the manufacturers make it pretty clear how they want their boilers piped.

Unknown

Wow !

That header is shockingly wrong .

To start , all that copper was supposed to be black steel , and 2 1/2 inch diameter steel . They decreased both of them to 2 inch . And they joined the 2 copper headers into that copper tee the absolute wrong way . They left out what's called an equalizer pipe and a Hartford Loop - both very critical for a steam boiler to run properly . Good news is the basic building block to good near boiler piping is already there - The 2 big iron tees .

The heat exchanger does look like it connects to the boiler at the bottom - water shoots right through without picking up much heat . Can you tell us which way that circulator is pumping ?

The boiler they installed can put out 671 sq. ft of steam radiantion . That is a hell of alot . Can you tell us how many radiators you have ? To find out how big a steam boiler you really needed , you'll have to count the height and width of each radiator section , and count up the sections . By those numbers you can find out how many square feet of radiation the boiler should have been . I bet that boiler is grossly oversized . I highly suggest buying this book to help you size the radiators -

http://www.heatinghelp.com/shopcart/product.cfm?category=2-59

But for a ballpark guess , just tell us how many radiators you have .

I agree with the others that said separating the steam and hot water with different boilers is your best bet . And it'll save you alot of headaches , time and money in the long run .

Michael G.

Is there hope?

So do you think that I can get someone to fix this and make it work well? for both the steam and hydronics? or am I in a totally disasterous situation?

Ron Schroeder

There is always help

where do you live

Steamhead (in transit)

Thanks Bruce

that pic was one of mine.

Mike G- what a mess! First, they reduced the size of the steam pipes leaving the boiler. I believe on the Dunkirk Plymouth boiler series, the steam outlet tappings are 2-1/2 inch, and must be used in that size so the steam won't be moving so fast that it draws water up with it. This "wet steam" doesn't carry heat well at all.

Second, the tee where the two copper pipes join is wrong. You have two steam outlets crashing into each other there.

Third, it's copper. The soldered joints in copper won't "give" the way threaded joints will. Also copper expands more than steel when heated. The result is usually broken soldered joints, leaks and other nasty things.

Ron Jr. and others have gone over the problems with the way the heat exchanger is piped. I don't have anything to add there.

The one good thing I see is that there is part of the old header left. That's the pair of steel tees that connect to the steam mains, and where the copper comes in the back. If that were my job, I'd build a drop header on the Dunkirk and route the steam from that into the front of the old header, with a drip coming out the back of the old header. This "double-header" would make some really dry steam!

Here's a shot of a double-header we did on a Weil-McLain SGO-9. The new drop header is 3-inch, and it feeds into the old 5-inch header.

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Michael G.

Hastings-on-Hudson, Westchester County, New York, zip 10706

I live in Hastings-on-Hudson, Westchester County, New York, zip 10706. Dan Holohan referred me to a guy in Floral Park that is very good with steam and hopefully will come to Westchester...http://www.heatinghelp.com/getListed.cfm?id=210&Step=30

I hope that this can be fixed and somewhat reasonably priced.

Michael G.

heat exchanger

Just to clarify, could you specifically tell me how you would have piped the heat exchanger so that it will work well and so that I can instruct someone locally who may not have as much knowledge as you?

Also once I get all of the piping corrected, do you feel that it is ok to have one boiler for both the steam and hydronic systems?

Also, what about sludge? Will the new steam system continue to produce it? Will I always have to drain/clean it and if so, how?

Thanks soooo much!
Michael

Steamhead (in transit)

If I were doing that

I would have used two boilers: one steam, one water. This way you wouldn't have to fire the big steamer to heat those little hot-water zones. I would also have suggested an indirect heater for your faucet water, this would run off the small boiler and is much more efficient than a direct-fired heater.

Plate-type heat exchangers don't tolerate sludge well. If I needed to use a heat exchanger off a steamer, I would have used a side-arm type like an Everhot, and piped it so the boiler water circulating thru the exchanger's shell was able to travel thru more of the boiler and pick up more heat.

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Ron Schroeder

Well I am with Dan

Matts the guy to get in your neighborhood

Steamhead (in transit)

I'll second that

Matt "Mad Dog" Sweeney has installed a brand-new steam system in his own home, and it works great. If he can make that happen, he can fix your system.

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Michael G.

cleaning steam systems

Also, is it possible/necessary to clean/flush steam systems? How would I do it and how often will I need to do it going forward with a system like this (once it is piped properly of course)?

JohnNY

A late-comer in this thread.

I'd like to add my two cents and say that the heat exchanger is absolutely misapplied here.
The boiler piping was done by someone who unclogs drains for a living (not that there's anything inherently wrong with that), but get him away from your boiler.

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Unknown

I'm with you, John, and all the rest...

I wrote this for just such an application, after working with the boiler and indirect manufacturer, along with the rep for the pump company. I learned a LOT that needed to be written down and passed on. Here it is.

This link includes the drawing and picture that are missing from this text...

http://hvac-talk.com/vbb/showthread.php?threadid=49435


Hot water zone on a steam boiler
by Noel Murdough

Frequently, there comes along a situation where a steam boiler is in a building, and it is desirable to add a hot water heating zone or an indirect water heater to the system. This can be done, but several concerns need to be addressed.

The first concern to remember is that there is no pressure in the system, at the water line. About 28 inches below the water line, it would be 1 PSI. Many residential boilers have a water line lower than that. We aren’t dealing with much pressure. This is a concern chiefly at the inlet to a pump, where low pressure combined with high temperature can cause the pump to cavitate. You can hear this happening, and it destroys pump impellers. In designing a pumped zone, you need to keep this from happening. Many people indicate that pumps won’t last long on a steam boiler because the water is gritty. They add a strainer to the pump inlet. Cavitation becomes worse in the pump. Usually, the water gets blamed.

Adding a strainer to a pump inlet, where the pressure to begin with is less than a pound, and the temperature is at or near boiling, will almost certainly cause cavitation in the pump. Piping to avoid cavitation is important.



A pump strainer can be added, but not right at the pump inlet. It should be installed at the boiler outlet, followed by the bypass tees, connecting the supply to the return of the zone around the boiler. By using this configuration, the water coming from the boiler would be strained, but the bypass water would be fed right to the pump inlet piping. A balancing valve should be installed in the bypass piping AND on the boiler piping.

You should make the bypass full sized, and pump with it wide open, to start. Adjust the boiler balance valve or the bypass valve, to maintain 180° F. supply temperature in the hot water zone with the boiler steaming.

As the pressure at the inlet is held steady by the expansion tank (the boiler itself, on steam, is the expansion tank), the water in the bypass pipe will be at about ½ PSI. The water at the pump discharge will be at a positive pressure. The strainer would severely restrict the inlet pressure of the pump, if it were piped after the bypass tee, right at the pump.

The indication that the strainer is becoming restricted will be a gradual reduction of heat output. If it were at the pump inlet directly, the indication would be a destroyed impeller in the pump.

The circulator absolutely must be installed as low as possible below the water line of the boiler. The only thing that keeps the static pressure at the pump positive is the weight of the water above it. It is imperitive to pump away from the boiler, to maintain positive pressure at the circulator inlet. Sometimes it is nessessary to throttle the return into the boiler AND the bypass valve to maintain a little head (resistance), so that the inlet pressure stays positive. Maintain a delta T across the zone that indicates a good flow rate.




Another advantage of piping it with a 180° supply temperature to the zone is that you can actually deliver twice the heat than if you designed for 200° supply temperature. If
you design for a 20 degree Delta T in your new zone, at 200°, your return water would be 180°, and not much water would go through the bypass. The ¾” boiler piping would provide 4 gpm, or 40,000 BTUH to the zone.

Now consider this…. If you design for 180° water, and 160° return water, you can design up to twice the BTUH load. Run 80,000 BTUH of baseboard (1”) and run a 1” bypass around the boiler. Use the same ¾” piping in and out of the boiler.

Run 8 GPM through the zone to get the 20° Delta T. Run the same 4 GPM through the boiler, except now it is 160° return water. That 4 gpm through the boiler is now at a 40° rise. That gives us 80,000 BTUH, which promptly mixes with the 4 GPM coming through the bypass at 160°.

Average supply temp is now 180°, with 80,000 BTUH added on the way by. All without pump cavitation.

The limit to the size of the pumped zone is the boiler pickup factor. Even this might not be what it seems. A target pickup factor is between one third and one half of the actual steam load connected to the boiler. In reality it can be much more, or even a little less. It is really important to know the amount of radiation connected to the system, and subtract that amount from the gross steam output of the boiler (usually about 80% of the firing rate). If the boiler is oversized to begin with, there might be quite a bit of load available for the water zone. NEVER use more than this number when sizing the new zone, or the steam side won’t heat properly when both run together.

The practical limit for height of the zone above the boiler is 30 feet. Since the pressure at the water line of the boiler is zero, the rest of the piping above runs in a vacuum. There must not be any vents or valves above the water line of the boiler. Any packing leaks would be an air leak INTO the zone, which will stop circulation. The shut-off valves and the purge/drain valves should be near, but under, the waterline of the boiler. A purge valve set-up should be on BOTH ends of the zone, so that it can be filled and purged with a hose. The boiler has no way to push water through to initially fill and purge the zone. Brass hose bib caps installed on the drain valves add security.

Wire the thermostat from this zone to bring on a pump relay that both starts the pump, and brings on the burner through a dry set of contacts, as the boiler control is likely to be 24 volts AC. Wire the burner thermostat contacts from the relay, but break one lead through a “breaks on rise” aquastat, installed in the boiler outlet piping to the new zone. It would be installed in the same general location as the strainer; before the bypass tee. It’s purpose is to stop the boiler from making steam, while allowing the water zone circulator to continue to run until the thermostat satisfies. If the steam heat thermostat calls at the same time, both zones will heat together, as the steam heat thermostat won’t be interrupted by the aquastat. Set the aquastat as high as you can, and still not make steam. Around 200° works well.

Indirect water heaters, and heat zones too, can be very effective if all of the details are taken care of.

DanHolohan

Thanks, Noel.

May I add that to Hot Tech Topics so that it sticks around?

Christian Egli_2

Palpitations

Thanks Noel, that information is brilliant -- why not remember everything we know about condensate pumps and vacuumizers cavitation and apply it to the hot water zone. You had to think of it, thanks.

Now that we're on a rolling boil

In the case of Michael G. who seems to have a big enough boiler (check?) and where there is a separating heat exchanger to make the hot water zone pitfall-free, here is a modification to rid the system of the pumped boiling hot water loop.

Why not feed the plate exchanger with steam taken off the header, steam is hot and steam is clean; it will cook the loop hot water without a problem. Spent steam would just dribble back down as condensate into the returns. This would prevent steaming interferences.

This is nothing special, of course, it's routinely used in larger systems, I just don't know how much in residential applications.

Just one more thought. The expert from Floral Park will sort all this out for sure. Go MD.

Michael G.

simplify

Thanks for this information. Is there any way that you can distill this information down to just a few sentences for a lay person who doesn't have this technical background?

I'll be happy to show this to Mad Dog or whoever else may come to fix my problem, but I'd like to better understand these suggestions and this is a bit too technical for me.

Thanks!

Unknown

Sure, Dan.

To Michael: Mad Dog knows this already. I think you will be happy with his steam skills.

To using steam in the heat exchanger: You would need to add steam zone valves to the steam system, which I'm not a huge fan of...

Noel

._4

.

Unknown

very late comer to this post

I hope u get a check from that dingbat who install the boiler! He proved why he shud not be workin on the system, god know how many more he did.... As others say, get rid of him, but first, get ur money back as u will needs to do it all over again with the RIGHT pro... U are lucky to have Mad Dog in ur area...

Michael G.

When you say that it needs to be "done all over again", I am presuming that the boiler itself is ok? And that I will need to redo the piping, and possibly the hydronic portion?

Michael G.

number of radiators

I counted and measured the steam radiators (not the hydronic baseboards that are also attached to this boiler, I think, right?):

10 steam radiators in whole steam system, sized as follows (all 6 inches deep):

1) Guest room: 33" x 16.5" (includes 13 sections, 1.5" x 16.5"
2) Bathroom: 13" x 20"
3) Girl's br: a) 19.5" x 16.5" (includes 8 sections 1.5" x 16.5") b) 23" x 16.5" (includes 9 sections 1.5" x 16.5")
4) Boy's br: 33" x 16.5" (includes 13 sections 1.5" x 16.5")
5) Livingroom: a) 48" x 16.5" (includes 19 sections 1.5" x 16.5") b) 33" x 16.5" (includes 13 sections 1.5" x 16.5")
6) Hallway: 12" x 16.5" (includes 4 sections 1.5" x 16.5")
7) Diningroom: 2 radiators both measuring: 30" x 16.5" including 16 sections each of 1.5" x 16.5"

I am not sure how to get the proper measurement to compare it with the 671 square footage that you quoted.

Does this help evaluate whether or not the boiler is appropriate?

Unknown

providing the boiler

Providing the boiler is properly sized for ur heating loads.. Boiler will be okay, its the pipings and hot water part needs to be redone....

Michael G.

proper size boiler

Does this help? How do I know if the boiler is the right size?

I counted and measured the steam radiators (not the hydronic baseboards that are also attached to this boiler, I think, right?):

10 steam radiators in whole steam system, sized as follows (all 6 inches deep):

1) Guest room: 33" x 16.5" (includes 13 sections, 1.5" x 16.5" 2) Bathroom: 13" x 20" 3) Girl's br: a) 19.5" x 16.5" (includes 8 sections 1.5" x 16.5") b) 23" x 16.5" (includes 9 sections 1.5" x 16.5") 4) Boy's br: 33" x 16.5" (includes 13 sections 1.5" x 16.5") 5) Livingroom: a) 48" x 16.5" (includes 19 sections 1.5" x 16.5") b) 33" x 16.5" (includes 13 sections 1.5" x 16.5") 6) Hallway: 12" x 16.5" (includes 4 sections 1.5" x 16.5") 7) Diningroom: 2 radiators both measuring: 30" x 16.5" including 16 sections each of 1.5" x 16.5"

I am not sure how to get the proper measurement to compare it with the 671 square footage that you quoted.

Unknown

Bringing this back to the top

You're movin' in the right direction , Michael . Next thing is to download Burnham's Heating Helper -

http://www.burnham.com/pdfs/htghelper.pdf

Page 42 shows you how to measure the radiators and find out the Sq. Ft. EDR .

Without doing the math I think the boiler is way oversized . Do the math to be totally sure though .

Michael G.

measurements

Ron Jr,

Thanks so much for the Burnham reference. When I do the math, it seems that I am about 200 sq feet or so for the steam radiators (assuming that the photo that they show on page 42 is considered a 1 column?), however, I don't know how that is affected by the adaptation of the hydronic system via the heat exchanger? Would that affect things? What happens if the boiler is grossly oversized? Especially since I bought the house with this new system?

Michael G.

I have a call/email in to Matt "Mad Dog" Sweeney and am waiting to hear back from him as to when he can make it here to Westchester. I hope soon. Thanks so much for your help. Will keep you posted. If you come up with any other ideas, feel free to write.

By the way, what is "pickup"? What does that mean?