Mueller Climatrol Furnace
I have a Mueller Climatrol Furnace VR8200A 2132 model that has been in the house for over 20 years. It recently started blowing cool air. Repairmen came and oiled the motor and that did not help so they replaced the motor and the fan switch. Now the furnace tuns for one minute and turns off for 2 minutes and then cycles. They then came and replaced my thermostat and it is still doing the same thing. Now they are suggesting I start looking for a new furnace. I have read that a dirty burner could cause this, or a bad flame sensor could be bad. I don't know where to look.
Any suggestions?