Boiler won't cut out

NewHomeNewbie

I have a boiler less than 10 years old. Worked fine in prior years. This year saw the relief valve blow and realized that it wasn't cutting out. It turns on fine but seems to just keep running while thermostat is calling for heat without cycling out. The gauge did not seem to show any pressure so thought it could be clogged. Cleaned the pigtail and pipe leading to the pressure gauge and still having the same problem. The pipe leading to the gauge and pressuretrol does not seem to warm up at all but is not clogged. Any thoughts on what it could be?

nicholas bonham-carter

Wild pressure

There could be a clog inside the boiler-pressuretrol tapping, which could be dangerous!!!! Luckily your relief valve worked. The entrance to the pressuretrol could also be plugged, so it is time to investigate this problem ASAP!!!--nbc

crash2009

Might be

 time to get the water side serviced?  Sounds like it's plugged maybe on the inside of the boiler, inside the pigtail, or where the pressuretrol meets the pigtail.  Sometimes its the bottom part of the pressuretrol (the diaphram).  If you are up to it, take it all apart and clean everything.  Might be a good time to add a T and an additional 0-3psi gauge.  It's probably time for something else to plug up as well. 

BobC

Blocked port?

Crash is right on the money about the probable causes. Did that pressure gauge usually read something or has it always just read zero?



If you take the pressuretrol off and turn it upside down and look up into the threaded bushing that screws onto the pigtail you will see a 1/16" hole that has to be clear so you can see the diaphragm. A;so when you take the pigtail off the boiler make sure the port into the boiler is clear, sometime a flap of crud forms that seals over that port when pressure starts to build but will let you blow into it because that flap gets pushed away from the hole. Use a piece of coat hanger to be sure that port in open and that there is no crud around the port that might get pushed into the opening and sealing that shut.



If your pigtail is mounted off a LWCO that feeds from the lower bushing of the gauge glass that pipe could be clogged (not common). If the pigtail mounts off the top of the gaude glass the gauge glass ports might be blocked. that means you have to remove the gauge glass and use a wire to be sure those ports are open.  If the gauge glass is bouncing around when making steam those ports are probably ok.



If your not comfortable doing this yourself call someone in. It's very easy to break a gauge glass when removing it and it might not be easy to get one on a Saturday.



Bob

Hen

Could be problem with electrical connection to the pressuretrol

The electrical connection to the pressuretrol could be the problem, no?

(Had a new boiler put in by a licensed plumber years ago. Right after that, each time I went in the basement I found a puddle of water underneath the pressure relief valve pipe.  Soon, I realized that luckily the pressure relief valve is doing its job, as the pressure gauge was reading sky high; 15#  I believe it was.  Looking things over,  I discovered that they forgot to connect the pressuretrol wires! The pressuretrol was just sitting there like a fancy decoration!)

NewHomeNewbie

Thanks!

Thank you for all the suggestions. The feed coming from the LWCO into the pigtail was clogged. Cleared that and it is now cycling as it should. The gauge is also reading properly and not broken as I thought it was. Thanks again.

NewHomeNewbie

Thanks!

Thank you for all the suggestions. The feed coming from the LWCO into the pigtail was clogged. Cleared that and it is now cycling as it should. The gauge is also reading properly and not broken as I thought it was. Thanks again.

STEAM DOCTOR

Why

The next question to answer is why did the pressure ever build up to 15 psi in the first place(the pressure relief valve on a steam boiler is rated to trip at 15 psi)? You should be able to heat the home without going over 2 psi. There might be some other underlying issues that are decreasing the efficiency of the system.