Status LED is solid on with no flashing pattern; the furnace is not responding to the thermostat.

Safety First: Turn off power before moving thermostat wires on the control board.

A steady LED usually means the board has power and is idle.

• Check thermostat: Ensure it is set to HEAT and the setpoint is above room temperature. Replace batteries if applicable.
• Bypass thermostat (advanced): At the furnace control board, briefly jumper R to W with a small piece of insulated wire. If the furnace starts, the thermostat or thermostat wiring is likely faulty.
• Inspect low-voltage wiring: Look for breaks, loose connections, or corrosion at the thermostat and furnace terminals.
• Check safety switches: Ensure the blower door switch is fully depressed by the door. Some models will not respond if the door is off.

When to call a professional: If the furnace does not respond even when R and W are jumpered, further control board or safety circuit diagnosis is needed by a technician.