I have an older Tempstar furnace that has developed intermittent failures since late december. The thermostat tells the furnace to start (heat on), the furnace starts up, but sometimes one of three things happen:
1. The pilot fails to ignite the flame
2. The pilot lights the flame, but only a small flame on one of the three burners stay lit.
3. All three burners light, but then go out within a couple of minutes.
This "failure" has occurred three times, but after 5-12 hours the furnace starts up fine and provides heat for the next few days.
I've had it looked at and of course it was working at the time so I didn't get any answers except the suggestion to replace it because it is old.
I realize that replacement is probably inevitable but I would prefer to do this in the spring as I would like to make some repairs in the utility closet.
Any suggestions for DIY maintenance or specific tasks for a professional would be appreciated.
If this furnace has a standing pilot ,I would suggest cleaning them. sometimes over time the pilot orifice gets partially restricted and makes the pilot smaller and usually creates orange feathering on it. This smaller pilot can easily loose contact with the thermocouple and cause intermirrent shut-downs.