Furnace does not respond to thermostat; status LED shows 10 flashes repeating; no call for heat recognized.

Safety: Turn off power before working on low-voltage wiring to avoid shorting the control board.

Steps to check:

• Verify thermostat mode: Ensure the thermostat is set to HEAT and the setpoint is above room temperature. Replace batteries if applicable.
• Inspect thermostat wiring at furnace: Remove the blower door to access the Luxaire control board. Confirm the R and W wires are securely attached and not broken or corroded.
• Bypass thermostat (test only): With power off, temporarily connect a jumper wire between R and W on the control board. Restore power. If the furnace starts a heat cycle, the thermostat or thermostat cable is likely faulty. Remove jumper after test.
• Check for shorts: Inspect the thermostat cable along its run for staples through the insulation or damage.

When to call a pro: If wiring and thermostat are good but 10 flashes remain, a technician should test the control board and replace it if necessary.