Pilot Going Out...

Unknown

too much draft.

I have experienced this on many atmospheric boilers especially when set up on cinder blocks that are open in between. The increased space below and the extra draft caused by it sucks the flame off the pilot.

To prove this is your problem, if your boiler is on blocks just slide a piece of panning across the top of them and wiat to se if it happens again.

PJO_5

He tried many things, but it keeps happening

Wallies,

It's been a while, but I have a wierd problem that The Wall will solve.

This guy has a boiler that has been in place for at least ten years. It is recently having problems with the pilot going out since the start of the heating season. Replaced the thermocouple and gas valve, cleaned out the tubing, etc. and it still keeps getting blown out.

This shares the chimney in this duplex with an identical system that is fine (no pilot/other issues), and no changes to either system of the chimney in recent years...is it a gremlin?

Thanks, PJO

Dale

pilot outage

Since you replaced the most common parts I have 2 more suggestions, 1st, what is the supply temp? If not at or over 140 degrees you may need a bypass since you may have a drop of condensate dropping on the pilot flame. A setback thermostat could have caused this. You could put a sheet metal shield over the pilot to see if this changes the outage cycle. 2nd you could have the cold junction getting too hot on a long burner run. You could shield the cold junction from radiant burner heat gain. This you can check with an adapter to watch the mv as the burner runs.

Al D'Ambola_2

Is there anything new in this home that can cause a negative pressure? Kitchen exhaust fan, some new type of mechanical device? I have seen recessed can lights installed on the 2nd floor of homes cause such extreme negative pressures in the basement, causing pilots to go out.

bill_71

you mentioned that there was an identical boiler on the other side of this duplex and it is running fine. separate gas meters??? it is possible the gas meter needs to be checked/changed by the g.c...... does the supply pressure stay constant with little to no drop in pressure when the main flame opens?? i recently came across a brand new aos water heater that kept going out because of the fluctuating supply pressures.

Floyd

PJO..

pilots are crazy animals indeed.... is the pilot flame lifting?
Does the burner light off with a big whooooosh???? does the cover over the flame keep the flame on the thermo???? Could be a the gas valve....sometimes the mv's of even a good thermo. won't hold the gv open. does the chimney have any obstructions, giving you flame rollout. Is there a flmae roll out switch that could be going bad and cutting out and then back in after it cools down??
I'm sure there a re more possibilties, but those come to mind right off...

Floyd

BTW, it looks like you changed jobs.. :-)

PJO_5

Thanks Guys!

As usual, the Wall comes through...

When the issue gets solved, I'll post an update. With the variety of repsonses and possible sysmptoms, it sounds like one of the above issues.

Take Care, PJO

Unknown

Patrick

I too would suspect something to do with a change with the gas being transmitted. Pilots are usually unregulated meaning that if a drop in pressure at or to the meter occurs, the piolt flame size will decrease proportionally. If you get so small that it can no longer generate enough DC current to hold the power unit open, the pilot will drop out. Also, have you checked the pilot orifice for possible blockage or crusting? You should always see about 3/8" to 1/2" of wash on the thermocouple. I would say check your incoming gas pressures to see if something is changing while other appliances are coming on.


Glenn Stanton

Manager of Training

Burnham Hydronics

U.S. Boiler Co., Inc.