excessive water use/loss

borowiec

We have a two-pipe steam system with a boiler that was installed two years ago. The automatic water feeder is coming on several times a day. For example, at 5pm on Friday the counter on the VXT-24 feeder read 54 and on Sunday at 10pm it read 63. As I understand it, those units are gallons, so that's way too much water. I have looked and listened carefully at all the radiators and all the walls where either steam or return lines run, as well as in the basement where pipes are visible, and at the outside walls, and I see no sign of moisture anywhere. None of the radiators are hissing, the only steam outlet is the valve above the boiler. It appears to be working properly, it shuts down when the pressure drops.

I know this amount of water consumption or water loss is bad, but I'm not sure what to do about it. Any advice would be appreciated!

ethicalpaul

Do you have buried return lines in the basement? Check for those. You will lose water when the boiler isn't running for that kind of leak. You should be able to see the water level go down considering your replacement amounts.

The only other option really is a hole rotted in the boiler, letting your steam go up the chimney. You should see great plumes of white "smoke" (really condensation) coming out of your chimney on a cold day.

ethicalpaul

Oh I just re-read that your boiler is only two years old? It shouldn't be a hole rotted in it in that case.

Also, what does this mean? "It appears to be working properly, it shuts down when the pressure drops."

borowiec

There are no buried return lines. There are a few hidden for brief stretches behind paneling in the basement, but they're all 2-3 feet from the floor and there are no signs of moisture at those walls. Most of the return lines in the basement are exposed. That's why I'm baffled: there is no possible place where there could be a leak that I haven't been able to check.

Re the steam valve, I only meant that it's not stuck open, i.e. always venting steam. It only opens after the boiler has run for a while (and usually shut off) when the pressure of the steam in the return line above the boiler rises.

We had everything serviced in early December, all is working properly. I'm not sure why the guy didn't mention the water use, the tag on the feeder shows that it used 109 gallons between January and November 2019. I don't know if he reset it; if he did, that means we've used over 60 gallons in less than a month.

Jamie Hall

The steam valve may be your culprit. If by steam valve you mean the main vent, which it sounds as though you do.

It should only be open until the main to which it is attached gets hot, indicating steam has gotten there. Then it should close and stay closed until the boiler shuts off and the pressure drops to 0. Then -- and only then -- should it open again.

If your description is anything like accurate (terminology can be difficult here), it's not working anything like the way it's supposed to -- and if it is venting steam, it could -- even if it a relatively small main vent -- be releasing as much as a gallon of water equivalent in steam every hour the boiler is running. And no, you wouldn't see a steam plume -- that would just contribute to the humidity in the basement.

KC_Jones

As a water usage reference point, my system has used 32 gallons in ~6.5 years, with a slightly smaller boiler.  Your usage is crazy.

The above comments cover most of the typical culprits for water usage.

One comment on the pipes behind panels.  I’ve seen. Water leak near a foundation wall, go between foundation and slab, and pretty much never seen.  I’m not in your basement, but if those hidden pipes are close to the foundation, I wouldn’t be so quick to discount them.

borowiec

The valve I was referring to is on the main return line, situated just above the boiler. I believe that is the main (and only) vent. I will check and report on it, I don't want to say something inaccurate. I do know that the plumber said that it was working properly when he did the service less than a month ago and nothing has changed about how it's behaving.

Yes, the runs of return lines that are behind paneling are on outside walls and those walls are below ground level, so there could be leaking there and the water is just dissipating into the ground. It would be a huge undertaking to open up those walls, though not as bad as having to dig from the outside. I guess that may be my next step...

JUGHNE

Could you show us pictures of your vent/valve that is leaking?
Also pictures of boiler piping from floor to ceiling.

acwagner

Try snugging up all the unions in your system--on the lines, radiator connections, etc. I found on my system those were the areas that loosed up over time and leaked. A bunch of small leaks can add up.

borowiec

All the unions that I can get to are snug, I checked that already. Mostly they're fused in place, the house is over a hundred years old. The radiator valves have all been replaced over the past few decades, none of them are leaking.
I will take photos of the vent and the piping tomorrow. The vent is on a return line and it isn't leaking. In fact, I just cranked up the heat to force the boiler to run , which it did for about fifteen minutes, but the vent did not open.

ethicalpaul

But that’s confusing. It should be open at the start of a call for heat to let air escape, then it should close when steam hits it (and remain closed until after the call for heat ends)

EBEBRATT-Ed

@borowiec

The water is going someplace and if your feeder is accurate your loosing a bunch. If you get a warmish day shut the boiler down and with the boiler cold-luke warm (not hot) fill the boiler up over the top until the supply pipe starts to get cold. Then shut the water off. Let it sit for an hour or so and look for leaks around the boiler.

Seems like with a two year old boiler your returns could be the most likely place.

Maybe you could make a few small holes in your walls and borrow a probe camera to look inside

JUGHNE

I have wondered for checking moisture inside a wall if a plant water moister indicator might work.
With hole poked into the walls with the pipes hiding inside and then compare to walls where you know no pipes are.
Bear in mind that exterior walls might be naturally moist from outside ground water.

Gsmith

You said this is a two pipe steam system, right? If so and if you have orifices on the radiators or radiator traps on the radiator outlets the main vent may never see steam (by design).

Does any of the radiators have an air vent on them too? If so, check there for steam leaks (a mirror can be used to see the steam).

Also recheck carefully at all the radiator valves, often the packing around the valve stem leaks, and as someone above said, a few little leaks can add up.

Jamie Hall

This is two pipe steam? That vent should never close. Ever. And the dry returns should never be more than maybe warm. I think you have more problems here than you may be aware of.

I might add that age does not prevent a steam system from working very well -- the centre part of Cedric's home is over 200 years old (maybe more like 250) and the youngest part is 130... The steam system (except Cedric himself) is young... at 90.

STEAM DOCTOR

Hooking toilet up to feeder would not cause feeder to open. You would have a toilet with no water. 

HarryL

Since the boiler is only two years old we have ruled out a hole in the boiler. Before ignoring that and digging up the basement it seems useful to confirm that the boiler is not the source of the problem. When we had a hole in the boiler it was not obvious to me that there was a lot of steam escaping through the chimney. It wasn't until we filled the boiler to near the headers and saw water on the floor that we realized that we had a bad boiler. Ours was about six years old at the time.

borowiec

The feeder is not feeding anything else, there is a water line going to the feeder and then a line to the boiler (and a bypass loop with a shutoff).

All the radiator valves and unions are tight and there are no leaks, that was the first thing I checked.

There are no vents on the radiators, they all have Mouat steam traps at the return line.

The vent on the main return line above the boiler only releases steam if we crank up the heat and the boiler runs for a long time. The last time that happened was when the plumber serviced the boiler last month, he raised the heat to 75F to test everything. And he said the vent (which is two years old) was working properly, so I don't think that's where the problem lies.

I have to conclude that a return is leaking in one of the three places where short runs of pipe are concealed in walls.

EBEBRATT-Ed

@borowiec

Since the boiler is only 2 years old it is probably not the boiler but before you tear down walls i would flood the boiler to check it

borowiec

If the boiler were leaking anywhere I would be able to see it, as it stands by itself away from walls and everything is dry around it.

acwagner

If the leak is above the water line, steam will leak out and go up the chimney.

kenlmad

Mr. Borowiec,

Are the images that you provided in your discussion link below still accurate for your system?

https://forum.heatinghelp.com/discussion/167928/which-way-should-main-steam-pipe-from-boiler-pitch/p1

ethicalpaul

If it were the boiler the water would be going up the chimney as steam though. Only by flooding the boiler would you see the water on the floor. It seems so unlikely in a 2 year old boiler, but when you rule out the likely, only unlikely is left to examine.

And I'm sorry about my misguided response earlier about your vent. I thought it was a one pipe main vent, totally my mistake, corrected by @Jamie Hall

borowiec

@kenimad: Yes, those photos are still accurate, though a couple of shutoffs and connections for cleanouts were added by Gerry Gill to the return line that runs from the darkroom along the basement wall. If anything is leaking, that's the only line that is partially hidden.

borowiec

Well, that was exactly the problem: a leak in the return line that was concealed behind paneling. There were dozens of old screens and storm windows in front of that paneling and yesterday the water on the floor did not extend as far as in the photo, which is why I missed this before.



Many thanks to all of you for you help and advice. The plumber is in the process of scheduling service.

JUGHNE

You are very lucky, is that pipe (leak point) above the water line of the boiler?
Could we see the actual leaking components when all exposed?

Often if condensate sits in a return pipe when it should drain, the bottom of the pipe rots thru.
Maybe there is a flat spot or pocket of water.

Jamie Hall

A suggestion... take out that whole section of pipe and replace it. If there's one area of leaking, there will be others!

ethicalpaul

Yeah, it's a great time to look at the return piping with fresh eyes. Sometimes they placed it in its current location because things in the basement were a lot different and no longer applicable.

borowiec

The leaking part is what you see in the photo, those are drops of water on the bottom edge of the pipe. Here is an enlargement. After I removed the rest of the paneling I did find one more, much slower leak. At that point that pipe is about three inches higher than the water line.

JUGHNE

At the boiler does the pipe drop down almost to the floor before connecting to the Hartford Loop?
And how is this dry return/end of steam main vented?
This might be an opportunity to add a tee for main vents??

borowiec

Yes, a Hartford loop was installed two years ago. There is a vent above the boiler at the main return.

JUGHNE

Can you show us where this pipe is connected at the boiler and the air vent for this pipe if any?

EBEBRATT-Ed

@borowiec
3" above the boiler water line is not a good place to be. It can cause potential water hammer. You need to raise the pipe or lower the pipe

If it was me I would lower the pipe and make it a true wet return. And it is ok to use copper tubing for that if you stay below the water line

borowiec

I understand that the pipe should be lower but lowering the whole run from the leak to the boiler would be very expensive and wouldn't solve the problem, as it would be impossible to lower the section that connects to it from the left, as that section is behind walls and under ground. So there would always be a section above the water line. The pipe in the picture is below the water line by the point where it goes into the next room.
In any case, the plumber will be here next week and will know the best thing to do.

ethicalpaul

the plumber will be here next week and will know the best thing to do.

hmmm....

EBEBRATT-Ed

@borowiec

You have to use caution with steam with the correct pipe elevations.

The boiler you have is likely not the original boiler to the house. The original boiler likely had a much higher water line putting the returns under water.

When the boiler was replaced the water line was likely lowered. Don't create more problems. Lower that pipe even if the others can't be lowered