It could well be. If the thermostat is calling for heat then there should be electric power to the main valve, usually switched by a power transistor on a pc board. If you have power to the valve solenoid coil but no main gas then it is the main valve coil. This can be tested with an ohm meter to prove it. If it's an open circuit then it's a job for a gas registered (corgi if in UK) plumber i'm afraid. If you have no power to the coil then it could be the pc board or even the thermostats (tank and room) havin a bad contacts or turned right down (or off). Most boilers also have pressure balance pipes and thermocouples which also affect whether or not the boiler fires up or not. Check for splits in rubber pipes etc. Any more than this and you're on dangerous ground. hope this helps some1 out there
Max Richards, August 2006
