Thermostat frequently reboots or restarts on its own

Safety first: Turn off power to the HVAC system before tightening or changing wiring.

• Step 1 – Check mounting and connections: Ensure the thermostat is firmly seated on the wall plate and that all low‑voltage terminals are tight.
• Step 2 – Inspect cable: Look for any visible damage to the thermostat cable between the thermostat and indoor unit. Repair or replace damaged sections.
• Step 3 – Measure voltage: With power on, measure 24 VAC between R and C at the thermostat while the system is idle and while it is calling for heat or cool. Voltage should remain stable (typically 24–28 VAC).
• Step 4 – Check transformer size: Confirm that the transformer VA rating is sufficient for the connected equipment and the iComfort thermostat. If multiple accessories are powered, a larger transformer may be needed.
• Step 5 – Replace thermostat: If power is stable and wiring is sound but random reboots continue, the thermostat’s internal power circuitry is likely failing and the thermostat should be replaced.