Rheem
No Cooling Call Reaching Outdoor Unit
Thermostat calls for cooling but the air conditioner does not start; indoor blower may run.
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Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
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Possible Causes
Open Y1 control wire between thermostat and indoor board, Blown low-voltage fuse due to short on Y circuit, Failed Y1 output on thermostat, Faulty contactor coil or outdoor control board
How to Fix / Troubleshooting
Safety first: Turn off power to indoor and outdoor units before opening panels.
Steps:
- Check thermostat display: Confirm it indicates a call for cooling.
- Inspect Y1 wiring: At the thermostat and indoor board, ensure the Y1 wire is secure and not broken.
- Measure 24V at indoor board: With a cooling call active, measure between Y1 and C at the indoor board. If no voltage, the thermostat or wiring is suspect.
- Check outdoor contactor: At the outdoor unit, measure 24VAC across the contactor coil when cooling is called. If voltage is present but the contactor does not pull in, the contactor coil is likely bad.
- Inspect low-voltage fuse: If the fuse on the indoor board is blown, locate and repair any shorts in the Y circuit before replacing the fuse.
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Repair Difficulty
Hard
4/5
Required Part
Y1 Cooling Control Circuit / Contactor Coil
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