Boiler repeatedly starts and stops (short cycling) with only brief burner operation.

Safety: Surfaces may be hot; take care.

• Open more radiators: Ensure enough radiators are open to absorb the boiler's output.
• Check thermostat location: Avoid placing the room thermostat near heat sources or in direct sunlight.
• Adjust boiler output: If user-accessible, reduce the maximum CH output setting on the Beretta boiler according to the manual.
• Technician – sensor check: Verify flow and return NTC readings and replace if faulty.