Furnace frequently cycles on and off, short burner run times, room temperature unstable

Safety first: Adjust only user-accessible controls unless you are a qualified technician.

Steps:

• Check thermostat location: Ensure the room thermostat is not near heat sources, drafts, or direct sunlight.
• Adjust boiler output: On modulating Intergas models, reduce the maximum CH output or flow temperature to better match the system.
• Improve flow: Open radiator valves fully and ensure all zones are balanced so that sufficient water flow passes through the boiler.

If short cycling persists, a heating professional should review system design and may recommend adding a buffer tank or reconfiguring controls.