Status LED flashes 14 times; furnace may not respond to thermostat or may short-cycle

Safety first: Turn off power to the furnace before changing thermostat wiring.

• Inspect thermostat connections: At the furnace control board, verify that R, W, Y, G, and C wires are correctly landed and not touching adjacent terminals.
• Check for shorts: Remove the thermostat from its base and see if the code clears. If it does, the thermostat or its base is likely faulty.
• Use R–W jumper test: With thermostat wires disconnected at the furnace, temporarily jumper R to W. If the furnace operates normally, the thermostat or cable is the problem.
• Verify thermostat compatibility: Ensure the thermostat is rated for conventional gas furnaces and not configured for heat pump or proprietary systems.

Replace the thermostat or repair wiring as needed, then restore power and test operation.