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-   -   Help With Steam Boiler (http://www.diychatroom.com/f17/help-steam-boiler-119467/)

bpm 10-07-2011 04:51 PM

Help With Steam Boiler
 
I have a Weil McLain EG-65 Boiler, natural gas fired one-pipe steam system. It was shut-down for the summer months and I just restarted it for the heating season, but I'm having some trouble. The thermostat is working properly and calling for heat when it should, but the boiler is cutting out due to the pressure switch. It is currently set to cut out at 2psi. At this setting the boiler hardly comes on for more than a few minutes, and when I last checked, even after being off for several hours the pressure guage was still reading 2psi and I couldn't force the boiler on by raisng the temp on the thermostat. I think there may be a problem with the guage and switch because there doesn't appear to be any actual buildup of pressure in the boiler. I even opened the emergency relief vent and there's no pressure there. All the vents on the radiators and the main vent in the basement seem to be working fine. The pressure switch is a Honeywell PA404A 10092 model. The boiler is about 30 years old and I suspect the switch is of similar vintage. Any thoughts or suggestions would be greatly appreciated.

Master of Cold 10-07-2011 05:58 PM

Is the gauge and switch on the same tube?

bpm 10-07-2011 06:04 PM

Yes they are.

Master of Cold 10-07-2011 07:07 PM

Sounds like you have a blockage in the tube. See if you can remove the tube and clean it.
If you have popped the emergency vent, you will probably want to replace it.

beenthere 10-07-2011 09:33 PM

As cold said, clogged pig tail.

bpm 10-08-2011 09:19 PM

Thanks to Master of Cold and beenthere. The pigtail was clogged. I pulled it and cleaned all the crud out and put everything back. Now, if you wouldn't mind indulging a newbie's questions, I just want to make sure I understand how this all works. I have the pressure switch set to cut in at 0.5psi with a differential of 1.5 (cutout at 2psi). After reinstalling everything today I fired up the boiler to make sure it would work properly. I raised the the thermostat temp to call for heat and the boiler kicked on as expected. It started making steam and the radiators got hot as expected. My question is still regarding the pressure gauge and limit switch. At no time did the gauge indicate any pressure reading, but I'm not sure if it should have. If the boiler is making steam and the steam is traveling to the radiators, would it be normal for hte pressure gauge to read zero, or should there be some pressure there, albeit very low? Or, does the pressure in the boiler only buildup if the air vents at the radiators close? Again, sorry for the newby questions. I just want to make sure everything is working correctly. Thanks!

beenthere 10-08-2011 09:23 PM

Only if the vents are closed and the stat is still calling for heat. Its normal not to show presure until it gets colder outside.

bpm 10-08-2011 09:29 PM

Thanks for the quick reply. I never really paid much attention to the pressure gauge prior to now so I just wasn't sure what I should be seeing. I'll pay more attention as the weather gets colder to see how the boiler behaves. I'm just glad things seem to be working normally now!


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