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Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 6022
Experience:  Retired HVAC/ Electrical & Boiler contractor. Industrial
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I have a Williamson Temp-O-Matic gas furnace - 2 side by

Customer Question

I have a Williamson Temp-O-Matic gas furnace - 2 side by side. My system fans are not coming on when running air conditioning and my HVAC service believes it's the fan limit switch needs replacing. Is there a source to go to for this part or an alternate part to substitute?
Submitted: 1 year ago.
Category: HVAC
Expert:  Rick replied 1 year ago.

Welcome to Just Answer, my name is ***** ***** I will do my best to help you with your issue. If my initial response doesn’t answer your question then let me know and we can continue our conversation

While the fan will run continuously with the fan side of the Fan/Limit jumped out the Fan/Limit is for heat only. Replacing it won't solve your AC problem. There is a fan center relay that controls the fan for AC.

Customer: replied 1 year ago.
Is the fan center part or an alternate available somewhere?
Expert:  Rick replied 1 year ago.

Yes, it sounds like this in an old unit so I don't know the part number offhand. But it's a pretty common relay. If you remove the old one and take it to an HVAC or many plumbing supply houses they should be able to give you a suitable replacement.