Heating, Air Conditioning, Fridge, HVAC/HVAC heater humming and buzzing


QUESTION: I had the AC heater set at 73 degrees and last night it started making a loud buzzing sound followed by a deeper buzzing sound (almost humming). I noticed it stopped heating. I opened the central heating unit door and noticed that the noise seems to come from here. Since it smelled like burning I turned it off.

ANSWER: What kind of heating system is it?  Gas, elect etc...  A model and Ser. number might be helpful too..

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QUESTION: I hsve a Trane electric hvac tvf036a140a1. It just started making a loud buzzing noise, apparently coming from the central heating unit. When I opened it and took the filter off, it smelled like burning.

Well, with the response, I know what it can't be.  The two common things in there that would buzz are is the transformer and fan motor.  You need to use a meter and check to see the transformer has voltage going in (208-240v depending on your power coming into the home) and 24v coming out.  If the transformer checks out then I would start looking at the fan motor.  I believe this is an older unit, so you will have fan motor that uses a run cap.  If the motor is humming, you might get lucky and just need to replace the run cap, otherwise the run cap and fan motor will have to be replaced.


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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