my space saver 38/50 boiler refuses to fire up.pilot light working normally. thermostat in heat position, timer set as per normal still refuses to work. Have just fitted a new thermocouple to no effect. all timers thermostat and gas valve knobs in on position, plus live power to gas valve but still not working. -- could gas valve be u/s. any ideas or suggestion welcome before i commit to new boiler. many thanks.

Andy, May 2009

If there is live/negative 240 volts to valve if valve is 240 volts solenied and that should click when power applies than it a gas valve solenied fault or if clicks and not fire than diaframe in gas valve not lifting so you can give a tap and see it works than or you need to change gasvalve.

Mr K, May 2009