i have a warm air heater system.i have switched it back on for the coming cold weather.pilot light works and thermostat works.but when the thermostat clicks in the gas burner doesnt fire up.could any one please tell me why the burner deosnt fire up.
Hi, difficult without circuit diagram which is not available online it seems but a number of things could be reason, eg.
most warm air systems run the fan(s) on slow speed to purge the system before allowing the main gas valve to open, the fan may be stuck, or the air flow switch may be not operating.
Or the gas valve its self may be stuck,
Or the thermocouple or other flame sensor may not be 'seeing' a good enough pilot flame.
Or even, is there a time clock not correct?
After quick check on obvious call in 'Gas Safe' registered fitter!