Furnace is from 1981, I can't afford a new one so I am trying to get by-
Here is what happens-
The thermostat calls for heat (I hear a click at the thermostat). The intermittent pilot will light (sometimes it will spark 10-15 times before it will ignite). After the pilot lights, the main burners do not come on. Sometimes it is cold in the house (+/- 55 degrees) in the morning, and I assume the pilot has been burning all night without igniting the main burner. This doesn't always happen, but probably it does happen 2 or 3 times a day.
The owner's manual states that after approximately 20 seconds the flame sensor heats-up enough to energize the main gas valve (the gas valve is a White-Rodgers 36C94, type 243).
To fix the problem, I turn off the electricity to the furnace, wait a few minutes and then turn it back on -or- turn the thermostat set point below the room temp., wait until it clicks and then turn it back up.
The pilot then lights and after 20-30 seconds the sensor heats up, I hear a click and then the main burner kicks on and then about 10 seconds later the blower comes on?.all as it should
This fix works all the time.
Anyone have an idea about what is going on here??
THANKS!!