Keeprite
No Response to Heat Call
Thermostat is calling for heat but furnace does not respond; LED on furnace is on and shows no fault code.
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Possible Causes
Broken W thermostat wire, Faulty thermostat relay, Loose connection at control board W terminal, Control board input failure
How to Fix / Troubleshooting
Safety: Turn off power before moving thermostat wires.
Steps:
- Verify 24V: Confirm ~24VAC between R and C at the control board.
- Test W input: With thermostat calling for heat, measure between W and C; you should see ~24VAC. If not, the thermostat or wiring is faulty.
- Jumper test: Temporarily jumper R to W at the control board. If the furnace starts, the thermostat or its wiring is the issue.
If the furnace does not start even with R and W jumpered, the control board is likely defective and should be replaced by a technician.
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Repair Difficulty
Easy
2/5
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