[205HVAC]

My gas furnace blower motor will not operate when the tsat is in AUTO. It will operate in RUN. The furnace does light up in both modes but only shutdown when tstat in AUTO.

Also, where can i get the service manual or wiring diagrams on this furnace.

Luxaire Furnance model: PCMU-LD16N095B

 

[COLDIRON]

Sounds like a defective fan control not turning on the fan when it reaches the proper run temp and this is causing the over temp safety to shut down the burners. The reason it runs when in the run/on is the fan is started by the cooling relay not the fan control.

 

[diyorpay]

Wiring diagram often on back of blower door.