Rheem
No Heating Call Reaching Equipment
Thermostat calls for heat, but the furnace or heat pump does not start; the fan may or may not run.
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
Open W1 or Y1 control wire, misconfigured system type (set to cool-only), failed W1 output on thermostat, blown low-voltage fuse on indoor board.
How to Fix / Troubleshooting
Safety first: Turn off power to the indoor unit before accessing wiring.
Steps:
- Verify mode: Ensure the thermostat is set to 'Heat' and the setpoint is above room temperature.
- Check configuration: In installer settings, confirm the system type (heat pump vs. conventional) and heat stages are correct.
- Inspect W1 wiring: Confirm the W1 (or W) wire is firmly connected at both the thermostat and the indoor board.
- Measure 24V at W1: With a heat call active, measure between W1 and C at the indoor board. If no voltage, suspect the thermostat or wiring.
- Check low-voltage fuse: Replace a blown fuse only after checking for shorts in the thermostat wiring.
- If voltage is present but no heat: The issue is in the furnace/air handler (limit switches, ignition, etc.) and should be diagnosed by a technician.
Advertisements
Repair Difficulty
Hard
4/5
Required Part
W1 Heating Control Circuit
Check Price on Amazon
We may earn a commission from links on this page.
Advertisements