Replaced motor blower 3 yrs ago. The pilot light is lit, the furnace is running but when I check the vents it is blowing out just barely warm air. I replaced filter and batteries in thermostat. What else can I do?

Take the cover off the burner compartment of the furnace. Find the model of the furnace on the rating plate of the furnace and post it here.


Carefully observe the sequence of events that occur when you turn the thermostat up and describe them here.