Steam bath in the boiler room

JohnMansolf

I'm troubleshooting a Weil McLain 380 steam boiler. The boiler room has been filling up with steam from the condensate tank vents and water bubbling out of the main air valves. The piping is a two-pipe gravity system with a wet return. There are no traps, only air valves. When I started the boiler, I noticed that the condensate pump filled the boiler to the top of the sight glass. I replaced the 15-year-old pump control and low water cut-off. (The head replacement is recommended every 5 years.) When I started the boiler, the pump control and low water cut-off filled the boiler halfway up the sight glass and stopped. This morning, the boiler is up to temperature. My concern is that the water level is almost to the top of the sight glass. Am I overreacting, or should I be looking at other symptoms? The wet return has a 6-foot-high loop before going into the condensate tank. The water level in the condensate tank is normal and gets flushed every year. Should I install a drain to flush the wet return before the loop?

Mad Dog_2

Pictures please..Mad Dog

Pumpguy

Ordinarily I would say you have leaking trap(s), but you say no traps.

We need more information to identify what type of system you have.

Based on the limited information supplied, I'm guessing you're operating with too much steam pressure.

What is the operating steam pressure?

JohnMansolf

1.5 PSI Pictures shortly

Steamhead

Why do you even need that condensate pump?

JohnMansolf

The condensate is part of the existing system. Here are some pictures to see what I am looking at. Thanks in advance

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20250416_132708.jpg

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ScottSecor

Based on the right low water cutoff (MM #150) and the gray tank in you photo above. I think your tank is actually a boiler feed tank. I tried to read the scale on your pressure controls, I cannot make out the numbers.

Boiler feed tanks have a feedwater pipe that allows city water to automatically fill the tank when needed. In you case I suspect there are two possibilities, you may be able to simply lower the pressure setting to prevent steam from blowing back to your boiler feed tank. On the other hand, your boiler feed tank may be overflowing due to a faulty feed valve/ballcock.

JohnMansolf

The pressure controller is set to 1.5 PSI, and the diff is set to 4 kPa. The reset controller is set to 3 PSI. I have # 35 air valves in the returns which are rated for a 3 PSI. The condensate tank has about 8 inches of water in it. We have not had a steam bath since replacing the McDonnell & Miller 150s. Then again, it has not been very cold😏

Seems pretty normal except for the higher than normal water level in the sight glass (1st picture).

Steamhead

Unless you've got a really short "A" or "B" dimension, you likely don't need that condensate pump. If you get rid of it you can get rid of some moving parts and servicing issues. Where are you located?

JohnMansolf

Connecticut, I know what you mean.

Steamhead

Try @Charlie from wmass , I think he comes to CT:

https://heatinghelp.com/find-a-contractor/detail/charles-garrity-plumbing-and-heating/

Charlie from wmass

The issue that will come up when the tank is removed is that there is no venting. You'll also need to double check the fire rate of the boiler against the connected EDR. I'm not saying to check the rating on the boiler but to actually clock the meter.