Thermostat is on but does not call for heat when room is cold

Safety first: Turn off power to the furnace/air handler at the breaker before adjusting wiring.

Steps to troubleshoot:

• 1. Verify mode and setpoint: Ensure the Emerson thermostat is set to Heat mode and the setpoint is several degrees above the current room temperature.
• 2. Check schedule and holds: Disable any schedules or holds that might be limiting heat calls. Use a manual hold at a higher temperature for testing.
• 3. Inspect W/W1 wiring: Remove the thermostat and confirm the W/W1 wire is secure in the correct terminal. At the furnace board, verify the same conductor is attached to W/W1.
• 4. Confirm system type: In installer setup, ensure the thermostat is configured for the correct system (heat pump vs conventional furnace) and that heating stages match your equipment.
• 5. Test furnace directly (advanced): With thermostat removed and power on, briefly jumper R to W at the furnace board. If the furnace starts, the thermostat is not sending a heat call and may be misconfigured or defective.

When to call a professional: If the furnace does not respond even with a direct R–W jumper, an HVAC technician should inspect the furnace controls and safety switches.