Furnace cycles on and off rapidly (every 1–5 minutes) without reaching set temperature.

Safety: Turn off power before adjusting thermostat wiring.

• Check thermostat location: Ensure it is not directly above a supply register, in direct sunlight, or near heat-producing appliances.
• Review thermostat settings: Adjust cycle rate or heat anticipator according to thermostat manual for gas furnace operation.
• Inspect wiring: Tighten all thermostat terminal screws and ensure no bare wires are touching.

If short cycling persists with proper thermostat setup, the Alpha control board may require evaluation.