Boiler fires up for hot water but NOT for heating ?

If you have a central heating thermostat check that is turned up, it may be faulty. Also if you have y-plan heating it could be a faulty mid position or 3 port valve, normally in the airing cupboard. It has a microswitch which has to make a contact to tell the boiler to fire.I would need more info on your system to pinpoint the problem such as the controls you have etc.

Paul Kelly
March 2008

I would say you got a problem with motorized valve not operating on heating, you can bypass valve with lever on side of valve but it will need replacing as you will need hot water on to get heating

rob
February 2008