Furnace cycles on and off rapidly (every few minutes) with noticeable clicking from the thermostat.

Safety first: Turn off power before adjusting wiring.

• Check thermostat configuration: For digital thermostats, set the heating cycle rate (CPH) according to the furnace manual (often 3–5 cycles per hour).
• Inspect wiring connections: Ensure R and W wires are firmly attached at the thermostat and furnace.
• Relocate thermostat if needed: Avoid locations near exterior doors, windows, or supply registers.