Steam Boiler shuts down with pilot

Dale

What was the pilot valve you had changed? Was it a combination gas valve? How old is the boiler. If the burners shut down after 20 minutes along with the pilot and this is a standing pilot system where the pilot goes off only if the pilot portion of the main valves closes then my thought ( guess only not seeing the system) is that the thermocouple if there is one, is getting too hot at the (cold junction)end away from the flame. this could be for alot of reasons, but as the other post suggested this should be checked by a tech. My next guess, as to cause, is a partially clogged flue which limits the air movement from under the pilot assembly.

Eddie M

Boiler shuts down along with pilot

Lately my natural gas steam boiler shuts down when its been running for about 20 mins. I noticed right before it shuts down the first 2 burners start fizziling out then the whole unit shuts down along with the pilot. I had the pilot valve changed and the same problem. pls help

Empire_2

Lots of potentials

Could be just a good cleanning of the pilot orifice, excessive draft, Faulty Gas valve,...etc... Call a reputable co that you trust..

Eddie M

can the actual burners be dirty and clogged? or maybe the pipe that connects all the burners? can the gas pressure be too low or high also? will all these factors make the unit and pilot shut down?

Steamhead (in transit)

Eddie, this is

one for a pro. There are a whole list of possible causes, and any repairs must be made safely.

Fortunately, you can go to the Find a Professional page of this site to locate someone near you who can fix it.

"Steamhead"

Unknown

Eddie

Is this a Millivolt Gas boiler or in other words, will it operate when there is no power? If so then it is probably equipped with a second Pressuretrol (Seconondary High Limit). This second high limit should be set for a value higher than the operating limit as far as the pressure is concerned. If the pigtail or syphon of the operating high limit becomes plugged, then the pressure will continue to rise above the operating point and the second pressuretrol will shut down the burner. It will also inturrupt the pilot when this occurs to alert you to a problem or plugged operating limit syphon. If this is the case, you are best served by having a qualified individual disassemble and clean the syphon. Hope this helps.


Glenn Stanton

Manager of Training

Burnham Hydronics

U.S. Boiler Co., Inc.