When I try to put heater on there is no sound at all,no ticking etc and after short while red light comes on,any idea what problem might be,gas supply and 12v on.
Thanks for advice,EdnaEdna, it is probably one of 3 things.
The simplest is the control cable which goes between the wall switch and the burner module has become insecure at the burner module end and needs unplugging, a squirt of electrical contact cleaner and replacing.
The second most usual is the burner module has packed up and needs a new one.
Third possibility, a fault on the wall switch PCB