What is wrong with mine - first it was on then it was off, we fiddled with the boiler then it was on then it was off again.
I only bought the house a year ago and my sons moved in over last winter - no problems and I was lead to believe the boiler was fairly new
Not sure how we can help with no system details .. Type and make/model of boiler .. Oil .. Gas ..LPG ... whether a system pressurised with HW cylinder .. Combi with CH pump.. Open vented, Sealed with CH pump .. Gravity, etc.
is the boiler contolled by a room thermostat or a programmer, or does it just supply thermostatic radiator valves, can't help without information the more the better.