My 20+ year old external oil burner is misbehaving: It starts up only if absolutely cold (first thing in the morning) but shuts down after an hour or so and will only start up again if left for several hours. Reset button does not seem to help nor does turning up (or down) thermostat. Seems to me like it must be a faulty thermostat which is misreading temp and shutting down and looks easy and cheap to replace (sits on top of burner with two wires and temp dial). Any advice?

CharlesL, November 2009

Do the Radiators actually heat up while the boiler is running? if not Check the Pump it may not be working

otherwise you would be wise to get an EXPERIENCED and well equiped Service Engineer in, to check the thermostat with a Digital thermometer, there could also be a problem with the burner such as capacitor or just about anything

however in this instance and from your description my cash is on the circulating pump!!

www.elanar.co.uk, November 2009