Weil-McLain Boiler

Laszlo

This problem occurs only in the morning:
Pilot light stays on for about 4 seconds, then shuts off. This repeats, at intervals of about 10 seconds, for about 12 minutes. Finally the main gas ignites, but only for a few seconds. Shuts off, repeats like this for about 5 minutes. It finally stays on and works perfectly until the next morning.
Followed Weil-McLain's trouble-shooting guide. BUT, it doesn't say anything about a cycling pilot light. Any ideas?
Thank you all!

Alan(CaliforniaRadiant)Forbes

Sounds

like a problem with the ignition control module (ICM). After the pilot ignites, it has to report back to the module that it has succeeded to light. The module will then open the main gas valve.

Somehow, the ICM is:

1) only getting a weak signal and shutting down the pilot, or

2) getting the correct signal, but not performing the correct function.

I take the easy way and replace the ICM; if it still doesn't work, it's a problem with the pilot or maybe the gas valve.

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

don_52

pilot problem...

A standing pilot will have these type problems if;

the chimney is unlined ( read cold )

the chimney is lined And coming out of a "deep setback"
( read cold again )

once bouyancy is established everything will work fine.

this can, and often does happen with intermittant ignition
as well around here.

this is of course making the assumption that the burner,
orifice and thermocouple are all in good shape + there
are no other venting or combustion air issues.

is there a water heater( w/ standing pilot ) that shares the common flue?

does it have the same problem?