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Heating, Air Conditioning, Fridge, HVAC/Carrier outside unit Mdl# 25GBA330A300


When I turn on the thermostat to heat, the outside unit fan turns on & off frequently. On for 10 sec, off for 10 sec, repeatedly. Over, and over. There is a sound like gas going through the copper tube when unit turns on/off. Can you help steer me in the right direction please.
Thank you.

It appears the model number you posted is not valid.  I was not able to locate that model number on Carrier's site.  I was trying to determine what sort of controls are in it.  It is really hard for me to guess without working on it, but I would be suspect of the defrost board.  I would have to rule out other things before I just replace the board.  You may also rule out certain issues if the unit will run in cooling mode.


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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