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Heating, Air Conditioning, Fridge, HVAC/Trane heatpump: compressor side not running. Aux system working.


Issue was: Compressor was humming and compressor fan was not going on. Checked all the run capacitors and one was bad. Replaced with identical rated run capacitor (12.5 uF/370 VAC). Turned on system
no fan or compressor running. Even put back the old capacitor to see if the old symptom would re appear. No luck. I've checked the fuses. They are ok and new.

Now only the aux side runs and the comp delay indicator on the thermostat blinks continuously. This did not happen before.

I'm stumped.


Are you sure the hum is coming from the compressor and not the compressor contactor ? Many times when a contactor gets old they hum loudly sometimes, Did you check to make sure you have correct voltage feeding the outdoor unit? I know you said the fuses are good but do you have 220Volt at the compressor contactor?.If you have proper voltage feeding the compressor and it's humming ,your compressor may be bad.Typically when a compressor does not start it hums for a short time then the compressor internal overload opens ,then silence. If that is happening to you chances your compressor is locked up.Verify all three wires at the compressor are to make sure the wires are not deteriated and the compressor terminals are not rotted.Typically on a HP the outdoor fan wire goes to the defrost board. you would have bypass the board or check to make sure the fan switch is closed so power can be feed to the motor to see if your fan is OK.You should only have at the max. two run capacitor one feeds the outdoor fan and one feeds the compressor. If you have a dual capacitor then you only have one.You do not state the age of your HP. Certainly if it's old it certainly possible the compressor is locked and most times you can not free it. As a last resort ,if your compressor does not have a start assist kit installed from the factory, you can buy one matched to your compressor tonnage rating.Buy the type that has a potential relay ,start capacitor with three wire hookup. Buy online vs the electronic relay type start kit.

Heating, Air Conditioning, Fridge, HVAC

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40+ years diversified experience.An HVAC/Refrigeration Self Employed Contractor since 1986. NATE Certifield. Answer questions pertaining to Residential and Commercial Air Conditioning , Warm Air Heating, Heat Pump systems.Mechanical and Electrical troubleshooting of these systems.Be as detailed as possible when describing problem.Packaged unit or split systems.No appliance questions.


Installation and Troubleshooting, Mechanical and Electrical, in following areas, Refrigeration ( Walk In and Reach In Coolers and Freezers ) Commercial Roof Top and Packaged Heating/Cooling ( Natural Gas,Propane, Electric, and Heat Pumps ) Computer Room Air Conditoning Systems,Commercial Residential Packaged and Split Systems Air Conditoning and Heat Pumps.Warm Air Oil , Natural and Propane Gas Heating systems.

Graduated from Private Technical School in 1975. An HVAC/Refrigeration Contractor . Have Unlimited Heating/Piping and Cooling Contractor License.Limited Sheetmetal Contractors License.NATE Certifield. York Certifield Master Heat Pump Technician 1986. Served 33 years combination Active Duty Air Force , Air Force Reserves and Air National Guard in the HVAC/Refrigeration Shop/Mechanical Shop. Troubleshooting/Installing HVAC/Refrigeration Equiptment Worldwide. Retiring in 2003 as a Senior NCO ,and a Mechanical Superintendent.

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