Hi all,

I am working on my grandparent's Trane XR80 furnace, and it will only complete one cycle, shuts down, but the inducer keeps running (will not stop unless power is shut off even if I turn the heat off on thermostat) and after the house cools and needs heat again, the furnace does not come on, just the inducer keeps running.

Inspection of the pipes for blockage revealed badly rusted out pipes - they had a leaky chimney that let water in the pipes and rusted them out. Do the pipes have to run all the way up the chimney for the furnace to work correctly? Can I rig this up for them somehow in the shorterm?

The furnace will work for one cycle, but won't come back on. Is this related to the pipes, or should I try something else? Flame senser and HSI are good - I am thinking pressure switch or inducer motor? If I shut the power off and back on it will always do one cycle and shut down, but that inducer keeps running and the heater doesn't ever come back on. What do you think?

Thanks in advance for your help!
Mike

Update - I think the inducer motor burned up. It ran all night and now it will only hum. I just ordered a new one, but am curious if you think there was a circuit board / relay problem or if the motor going out would cause it to run 24/7 and eventually burn up? I am afraid that replacing the motor will not fix the root cause of why the first one died.

We are also addressing the flue issue.

Thanks,
Mike