Heating, Air Conditioning, Fridge, HVAC/Furnace fan


I have a Janitrol furnace model OLF140D60.
The blower runs continually, only time it shuts off is with the main circuit breaker to furnace. Have tried new limit control and new thermostat. The limit control button is pulled out. There is a capacitor at the blower. What does this do? it looks like a pair of old ballasts on florescent lights.
It has a separate heat pump which I have taken out of the circuit by removing the breaker outside and disconnecting the wiring from the thermostat to it.
I have no experience with furnaces but was an auto mechanic. I've been trying to find a wiring diagram to no avail. I'm working on this for my church so any suggestions would be helpful.

I was not able to find the model number you have listed.

The run caps are needed for the unit to run, and are not the cause.

At this point it is not possible to me to determine what turns the fan on.  You can trace the wires and take pictures then attach them to this site and I might be able to help determine what is keeping the fan running all of the time.


Heating, Air Conditioning, Fridge, HVAC

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Craig HVAC Expert


I have been in the HVAC field for the past 18 years. I can help with most HVAC questions. I work on commerical buildings for the most part, and have yet to find anything I could not troubleshoot and repair, when repairable. I work on small 1 ton units to a 2500 ton chiller. Troubleshoot air flow, elect, and control problems. I attend regular classes to keep up with the latest and greatest.


I work on commerical sites, hospitals, gov't buildings. I can troubleshoot just about anything in the HVAC business.

5 years trade school, VFD training classes, Liebert factory training, some York and Trane factory training.

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