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HomeRepair HelpTrane Central A/C RepairTrane Central A/C Condensing unit does not run Repair
Trane Central Air Conditioner Condensing unit does not run
When your Trane central air conditioner condensing unit does not run, a bad run capacitor or a tripped circuit breaker or blown fuse is the most likely cause. A failed compressor is a possible but less common cause. A failed compressor can stop refrigerant circulation and keep the outdoor unit from starting. A faulty Trane wall thermostat is another common cause because its contacts control both the furnace and condensing unit. Next, check the condenser fan motor and fan motor, which can fail electrically or seize when their bearings lock up. If the unit has power but neither the compressor nor fan runs, a sealed system problem, such as low refrigerant causing the low pressure switch to trip, may be responsible. A defective high or low pressure switch is less common. Testing a compressor, motor, contactor, thermostat, or pressure switch involves electrical hazards, and 240V line-voltage work should be handled by a qualified HVAC technician. Any refrigerant diagnosis, sealed-system repair, compressor replacement, or pressure-switch replacement requires EPA 608 certification and a licensed technician. Enter your Trane model number to find the exact replacement part for your specific central air conditioner.
01 - Trane Central Air Conditioner Compressor
Central air conditioners use a compressor to pump refrigerant through the condenser coils located in the outside condensing unit and through the evaporator coils mounted on top of the furnace or air handler. While it's not a common problem, if the compressor fails, the condensing unit will not run. You can use a multimeter to test the compressor for electrical continuity, a continuous electrical path present in the component, to help determine if the compressor is faulty. If all other potentially defective components, such as the capacitor and condenser fan motor, are operating properly, then a qualified technician should ...
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Highly Likely
02 - Trane Central Air Conditioner Wifi Thermostat
The WiFi thermostat has contacts in it that control the furnace. If the contact fails it can result in the furnace and the condensing unit to not run at all.
Common
03 - Trane Central Air Conditioner Condenser Fan Motor
A faulty condenser fan motor can be responsible for the central air conditioner condensing unit not running. You can use a multimeter to test the fan motor for electrical continuity, a continuous electrical path present in the motor, to help determine if the motor is defective. You can also use the multimeter to determine if power is reaching the motor. You can also try rotating the fan blades by hand. If the blades do not turn freely, it's likely the motor bearings have seized and the fan motor will need to be replaced.
Common
04 - Trane Central Air Conditioner Fan Motor
A faulty fan motor can be responsible for the central air conditioner condensing unit not running. You can use a multimeter to test the fan motor for electrical continuity, a continuous electrical path present in the motor, to help determine if the motor is defective. You can also use the multimeter to determine if power is reaching the motor. You can also try rotating the fan blades by hand. If the blades do not turn freely, it's likely the motor bearings have seized and the fan motor will need to be replaced.
Common
05 - Sealed system problem
If the condensing unit has power to it, the contactor checks out okay, but the fan and compressor are not running, it is likely that the unit is low on refrigerant which will cause the low limit pressure switch to trip and keep the unit from running. Since diagnosing and repairing a sealed system takes specialized tools and knowledge, a qualified service technician should diagnosis and repair the unit.
Common
06 - Trane Central Air Conditioner Pressure Switch
A pressure switch is a safety device used to help prevent component and system failures. There are basically three types of pressure switches used in central air conditioning and heat pump applications: High Limit, Low Limit, and Ambient Temperature. Depending on the model, you may have one or more of these or none. The pressure switch(es) can be checked with a multimeter, referencing the wiring diagram for the circuit locations. Note: If a pressure switch needs to be replaced the refrigerant will need to be removed, requiring a qualified technician.
Less Common
Frequently Asked Questions
Why is my Trane central air conditioner condensing unit not turning on?
How do I troubleshoot a Trane condenser fan that is not running?
Could a bad capacitor cause the Trane compressor and condenser fan not to start?
Can low refrigerant or a pressure switch keep my Trane condensing unit from running?
How do I find the correct Trane replacement part for my central air conditioner?
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