WM model 150 series 3...only 3 years old.
Temperamental bastard, flame lights comes on for 5-10 seconds and shuts off over and over ...
Ignitor replaced and unit cleaned 6 months ago.
Any idea how to troubleshoot?
Thanks.
Thermostat OK? Batteries not weak/leaking?
Those symptoms would point to a faulty flame detector assuming that besides the flame lights coming on, that it actually fires up at that point. It thinks that it has not fired up, so it shuts off the gas.
What do you mean by "flame lights"? Just some indicators, not the actual flame?
Many (all?) furnaces have a diaphragm that closes a switch once the exhaust blower (not the forced air blower) reaches operating speed. If that switch doesn't close after a short time, the furnace will shut down and try again and again if the thermostat keeps calling for heat.
There's a trick where you blow/suck on the tube to manually activate it the diaphragm. It's a way to check if the diaphragm/switch assembly is bad or if the exhaust blower itself has a problem.
My exhaust blower was sucking air past the gasket where it mounts to the chassis, reducing airflow to the diaphragm and causing it to be intermittent. A little silicon sealant solved the problem.
I read it as "the flame (burner) lights" and shortly thereafter shuts off.
That would indicate a flame sensor issue or a bad furnace controller.
Yes it *could* be read that way. It could also be read other ways, which is why I asked for clarification.
"flame lights comes on"
Is the OP describing indicators or the glow of the flame itself?
Bad grammar/lack of punctuation leads to confusion. Clarification might help.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.