I have an older temco wall furnace. My problem is that the blower motor fan runs off and on. It will run few seconds then shut off few seconds. Sometimes it will make a longer run but never runs a full cycle to bring room up to temp. Set thermostat to run longer cycle and didn't help. It has a filter light on front panel that is constantly switching on and off also,but not in sync with what blower is doing. Have cleaned the filters that are in blower compartment (some type of aluminum mesh) but still have problem. Blower motor gets hot to the touch but no smell. Had new bearings put in last winter and was working fine until now. Am I missing a filter somewhere? Or capacitor out? Any help greatly appreciated.

Without being there to see its operation and electrically test your unit it could be the motor,capacitor,or the fan switch that is activated by the heat out of calibration which usually means it need to be replaced.

Where is fan switch located ? I noticed too if I turn thermo all way down for a while and motor cools when I turn back up until hear click it runs fine and runs complete cycle. After that it goes back to on/off agan every few secs. Don't know if that helps diagnose anything or not. Thanks for any help.

Where is fan switch located ?

That is a good question and I do not have a answer since I have no information on your unit as to part locations.

The blower motor is in top compartment of heating unit. Fasco Distributers-115v-60amp 1500rpm-1/14hp.There are no oil lubricant ports that I can find. Below that is burner behind panel with sequences of what look to be 3 capacitors mounted on right side in vertical line.Filter light would be at top right corner of panel. Blower motor itself has what I believe is run capacitor mounted off to side of fan.

Quote:

---

Originally Posted by weemsy

...problem is that the blower motor fan runs off and on. Had new bearings put in last winter and was working fine til now.

---

Belt-drive? If so, turn off power & carefully remove belt. Check motor and blower for excess drag.

Not belt driven

What bearings were replaced?

Blower motor