The furnace short cycles: it starts, runs for a few minutes, then shuts off and restarts frequently.

Safety: Turn off the power before removing panels.

• 1. Replace filter: Install a clean filter of the correct size and rating.
• 2. Open vents: Ensure all supply and return vents are open and unobstructed.
• 3. Thermostat location: Ensure the thermostat is not near heat sources, direct sunlight, or supply vents that could cause rapid temperature swings.
• 4. Professional evaluation: If short cycling continues, have a technician check the temperature rise, limit switch operation, and furnace sizing relative to the home.