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Richard, Technical Manager
Category: HVAC
Satisfied Customers: 1514
Experience:  27 years of Experience, NATE Certified, professional trainer
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my thermostat works however there is a humming sound coming

Customer Question

my thermostat works however there is a humming sound coming out of it
Submitted: 7 years ago.
Category: HVAC
Expert:  Richard replied 7 years ago.

It sounds like a faulty thermostat. However if you look on the back cover can you get the complete model number and I can look it up to see if there could be something else. If this is a 24 volt thermostat check the voltage to the stat and make sure your with in 20-30 volts. Let me know the model when you can.

Thank you

Customer: replied 7 years ago.
CT51A1035 is all I can find on it... It is working just emiting a low humming sound. I don't have a volt meter on hand. Also, where would I find the voltage transformer. Could it be tied in to the door bell
Expert:  Richard replied 7 years ago.


No the transformer comes off the furnace or air handler. Take cover off the thermostat ( kill power at furnace first) and make sure everything is tight. If you can check voltage that would be great. However this is a standard thermostat and if your getting humming from it I would replace it.

Let me know how it goes.

Thank you


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