Thermostat calls for heat but furnace short cycles or shuts off quickly

Safety first: Turn off power to the furnace if you will be adjusting wiring or relocating the thermostat.

Steps to troubleshoot:

• 1. Check thermostat location: Ensure the Emerson thermostat is not directly in the path of a supply register or near exterior doors, which can cause rapid temperature swings.
• 2. Adjust cycle rate: In advanced settings, adjust the heating cycle rate or temperature differential to a lower cycles-per-hour setting appropriate for your system (e.g., 3 CPH for forced air).
• 3. Inspect W wiring: Confirm the W/W1 wire is firmly connected at both the thermostat and furnace board with no loose strands.
• 4. Monitor operation: After changes, observe several heating cycles to see if run times stabilize.
• 5. Rule out furnace issues: If the thermostat continues to call for heat but the furnace shuts down on its own, the problem may be with furnace limit switches or flame sensors rather than the thermostat.

When to call a professional: Persistent short cycling should be evaluated by an HVAC technician to prevent equipment damage and inefficiency.