Low water in sight glass & missing main vents (balancing issues)
Hello Heating Help Community,
I’m experiencing several issues with my steam heating system and would appreciate any advice. This system is brand new as of May 2024, so this is my first heating season with the boiler. Here’s what I’m dealing with:
Low water level in sight glass: When the boiler starts steaming, the water in the sight glass drops to about 1/2"-1", and sometimes even lower. After the cycle the water returns to the sight glass, by gravity/auto fill. I observed the low-water cutoff working properly (the intermittent level test triggered boiler then re-fired.) Also after the boiler quit the water level seems to drain further which then triggered the low water to illuminate on the cutoff.
The wet returns are as hot as the main piping, which makes me wonder if there's a problem with the steam condensing properly in the return lines or if there's a possible blockage or issue in the wet returns.
The system doesn’t have main vents installed. I’ve learned from previous discussions how important main vents are for proper system function, but I’m not confident in my ability to install them correctly. Could the lack of these vents be contributing to the water level issues or other system inefficiencies?
Just a few details and I'll also attach some pictures of the near boiler piping.
- The pressuretrol is set with the main (cut-in) at 0.5 psi and the differential at 1 psi.
- Radiator vents seem clear, and I haven’t noticed any steam leaks.
- I haven’t done any significant work on the system since it was installed, but I’m wondering if I need to make any adjustments to improve efficiency.
I’d like to troubleshoot these problems as much as possible and would also appreciate recommendations for professionals in Somerset County, PA (if there are any close on this site). After conversations with the installer, I’m not confident they’re the right crew for the job.
Please let me know if you need any more pictures and I'll figure out how to upload some video of the sight glass during firing. Thanks in advance.
Comments
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It looks like a combination of possible issues, your pressuretrol is set to cut out at 5 PSI, that should be more like 2 or less. The water in the sight glass looks like there is a layer of oils on top, the boiler needs to be skimmed. The equalizer is really tiny, the owners manual should show a minimum pipe size. The Hartford loop appears to be high. Both the size of the equalizer and the oils can cause the water level issues.
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Hmmm don't look at the literature pictures read the instructions.
And with looking at some of the other pictures " After conversations with the installer, I’m not confident they’re the right crew for the job. " I agree !!!
None seem to be in your area.
This may help too;
National - U.S. Gas Boiler 45+ Years Old
Steam 300 SQ. FT. - EDR 347
One Pipe System
2 -
Well I see some issues.
First of all it is safe to run the boiler if you can see the water in the sight glass. If you can't see it you shouldnt run the boiler.
Is this system 1 or 2 pipe steam? two pipes to radiators or 1pipe?
Your return piping looks like a false water line instead of a hartford loop.
Has the boiler ever been skimmed?
You must have a huge house for that size boiler how did they determine the size?
Looks like 2 steam mains capped off?? what is that all about?
Your pressure control looks like it is set for 5 psi cut out??
Why does the boiler have an aqustat? Do you have a domestic hot water coil?
Looks like a header drip or equalizer way in the back
yes you should have main vents
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@109A_5
Good catch on the sight glass drain.
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@Neild5 I've adjusted the pressuretrol. In the second picture, is this more in line where the main and diff should be set? Observed zero change to water level when steaming. It remains just above the lowest permissable level line for the majority of run time. I'll look into manual for equalizer pipe sizing, as well as a how-to on skimming. Thanks.
@109A_5 Good catch on the water gauge. I wish I could have caught this sooner. Going to call them on this. Thanks.
@EBEBRATT-Ed Judging by the first picture would you say this is safe to run? It's a two pipe system with vents. Not sure about the skimming, I'm going to look into a how-to on that. The building is a 7-unit apartment, I should have mentioned that. As far as sizing goes I trust they had an engineer involved although with the sight glass being installed upside down it's tough to say. The two mains capped off were piped to an old coal fired boiler that was removed. I posted a picture of adjustments I made to the pressuretrol does this look more in line to what the settings should be? Not entirely sure on the aqustat. My guess would be that it is there to help maintain the water temp internally for quicker steaming when system has been running? I'll raise this question to installer as well. Thanks.
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I was able to locate this table in the manual. I have the 904A model.
The piping in red is only 3/4" when it should be 2"? This could explain the water level drop and the occasional water hammer I experience from this area.
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The Hartford loop and the equalizer should be piped correctly.
With the water level where it is, and the LWCO probe position where it is, it is maintaining a minimum water line as it should. If you are loosing all that water during one steaming event you may have a leak. If all the water eventually comes back to the boiler you may have slow returns or the boiler does not have enough water capacity for the size of your system.
National - U.S. Gas Boiler 45+ Years Old
Steam 300 SQ. FT. - EDR 347
One Pipe System0 -
How long does it take the water level to drop that much? If it's doing it fast then I would suspect surging due to oil in the water.
I'm no advocate of oversizing an equalizer but neither would I ever want to see one as small as yours. I can't imagine what the installer was thinking there.
NJ Steam Homeowner.
Free NJ and remote steam advice: https://heatinghelp.com/find-a-contractor/detail/new-jersey-steam-help/
See my sight glass boiler videos: https://bit.ly/3sZW1el0 -
@ethicalpaul heres a video of the sight glass. I missed the first 30 seconds to one minute of the firing. This can't be normal?
@109A_5 Thanks for the reply. You're saying that 3/4" equalizer piping is correct and it shouldn't be 2"?
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@ethicalpaul I was always under the impression of the water must maintain in the center of the sight glass with little fluctuation.
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The water should be in the middle of the sight glass and be steady. Moving up and down gently about 3/4"-1" is ok.
I would have them come back, fix the gauge glass and show them what the water line is doing.
I think you need skimming but I also don't like the undersized the equalizer and the equalizer is not piped right. Check the manual. The tee and the elbow on the equalizer need to be swapped. The tee needs to be mounted on the pipe that goes into the boiler. Check what you have against the picture in the manual.
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I have 3/4" on the truck…
Trying to squeeze the best out of a Weil-McLain JB-5 running a 1912 1 pipe system.2 -
If there's not enough boiler water for the system.
Trying to squeeze the best out of a Weil-McLain JB-5 running a 1912 1 pipe system.0 -
NO, where did I say that !!!??? The Equalizer and the Hartford loop is a mess and needs to be fixed !!! Follow the manufactures instructions.
National - U.S. Gas Boiler 45+ Years Old
Steam 300 SQ. FT. - EDR 347
One Pipe System1 -
no it’s not normal. Well it’s normal if the boiler hasn’t been skimmed to clean the oils out
here’s the same thing happening to my old boiler before I knew anything
NJ Steam Homeowner.
Free NJ and remote steam advice: https://heatinghelp.com/find-a-contractor/detail/new-jersey-steam-help/
See my sight glass boiler videos: https://bit.ly/3sZW1el1 -
There’s always enough water for the system, since the boiler is by definition sized for the size of the system. At least in residential steam. We aren’t seeing this boiler run out of water due to making steam, we are seeing this boiler throwing its water into the pipes
NJ Steam Homeowner.
Free NJ and remote steam advice: https://heatinghelp.com/find-a-contractor/detail/new-jersey-steam-help/
See my sight glass boiler videos: https://bit.ly/3sZW1el
1 -
@ethicalpaul @EBEBRATT-Ed thanks guys, contacting them tomorrow to get this corrected. Will report back.
@delcrossv "we got 3/4" on the truck" it's seeming that way isn't it lol.
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It's sized for the radiators. (+/- some pickup factor) If the filled volume of the system including condensate taking it's own sweet time, exceeds the now miniscule volume of water in the boiler, Well, WM didn't include that diagram for giggles.
Boiler shooting water is more likely.
Trying to squeeze the best out of a Weil-McLain JB-5 running a 1912 1 pipe system.0 -
@ethicalpaul Just curious about when you remedied your situation what differences in performance can I expect?
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" Low water level in sight glass: When the boiler starts steaming, the water in the sight glass drops to about 1/2"-1", and sometimes even lower. After the cycle the water returns to the sight glass, by gravity/auto fill. I observed the low-water cutoff working properly (the intermittent level test triggered boiler then re-fired.) Also after the boiler quit the water level seems to drain further which then triggered the low water to illuminate on the cutoff. "
Is the drop in water level sudden or slow ?
If sudden then it probably needs skimming along with the other corrections.
National - U.S. Gas Boiler 45+ Years Old
Steam 300 SQ. FT. - EDR 347
One Pipe System0 -
You skim the boiler. Oils in the boiler cause it to foam and throw the water into the pipes. After the oils are removed, it will produce steam with minimal change to the water line.
Of course you have other issues at play with your piping, but hopefully your installer will address that.
New pipes have oil in and on them so if they install new pipes, that will make more oil that needs to be skimmed out.
here is another video. In this one, I added oil purposely to my new boiler to demonstrate what happens:
NJ Steam Homeowner.
Free NJ and remote steam advice: https://heatinghelp.com/find-a-contractor/detail/new-jersey-steam-help/
See my sight glass boiler videos: https://bit.ly/3sZW1el3 -
ADDED oil? Hats off to you @ethicalpaul That was selfless in your pursuit of the truth.
Trying to squeeze the best out of a Weil-McLain JB-5 running a 1912 1 pipe system.2 -
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FYI for slow returns
Trying to squeeze the best out of a Weil-McLain JB-5 running a 1912 1 pipe system.0
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