Thermostat calls for heat but furnace short cycles (turns on and off frequently)

Safety: No wiring changes are required for placement and settings adjustments. If you choose to relocate the thermostat, turn off power to the HVAC at the breaker first.

Steps to improve operation:

• Check thermostat location: Ensure the Sensi thermostat is not directly in the path of supply air, near a drafty door, or in direct sunlight. These conditions cause rapid temperature swings at the sensor.
• Adjust cycle rate: In the Sensi app or installer menu, adjust the cycle rate or temperature differential to a less aggressive setting so the system runs longer per cycle.
• Seal wall opening: Remove the thermostat and seal any large hole in the wall behind it with foam or putty to prevent wall cavity drafts from affecting the sensor.
• Relocate if necessary: If placement is poor, consider moving the thermostat to an interior wall in a representative room. Turn off power, label and extend wires as needed, and mount the Sensi wall plate securely at the new location.

When to call a pro: If short cycling persists even with good placement and settings, the furnace or heat pump may be oversized or have internal safety issues that require HVAC technician diagnosis.