E9
Payne
Thermostat or Control Signal Error
Payne system displays E9; indoor blower may run but outdoor unit does not, or vice versa.
Advertisements
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.
Advertisements
Possible Causes
Faulty thermostat, Broken Y or G control wire, Short between thermostat wires, Incorrect thermostat wiring
How to Fix / Troubleshooting
Safety: Turn off power to the furnace/air handler before accessing thermostat or control wiring.
- 1. Check thermostat settings: Confirm the thermostat is set to COOL and the temperature is set below room temperature. Replace thermostat batteries if applicable.
- 2. Inspect thermostat wiring: Remove the thermostat from its base. Verify that wires are firmly attached to the correct terminals (R, C, Y, G, W as applicable). Look for loose strands or shorts between terminals.
- 3. Inspect low-voltage wiring at air handler: At the indoor unit, check the low-voltage terminal strip. Ensure the Y and G wires are secure and not corroded or broken.
- 4. Bypass thermostat (advanced DIY): With power OFF, temporarily connect R to Y and G at the air handler terminal strip. Restore power. If the system runs normally without E9, the thermostat or its wiring is likely faulty and should be replaced or repaired.
- 5. If E9 persists: A technician should check for shorts in the cable, test the 24V transformer, and verify control board operation.
Advertisements
Repair Difficulty
Medium
3/5
Advertisements