My Potterton Suprima 60L system gas boiler will only heat up the radiators when a demand for hot water is given. The red fault light stays on and will not reset. The boiler 'tries' to fire up when the room thermostat is turned up - the fan cuts in, the relay klunks, the pilot light ignites - but it cuts out and the fault light appears. The only way to get it to work is when the bath, or shower or hot water tap is turned on for prolonged time and there is a demand for hot water in the tank. Please help. :(
htg & Steve the gas, thanks for info. Moved the spindle on the Honeywell valve (closest to Primary Flow from the tank) to MANUAL/ON but nothing obvious happened. Still only seem to have any heat in radiators when the hot water is demanded. Room thermostat set high, control panel set to Central Heating ON, not AUTOMATIC or ALL DAY. When hot water kicks the system in, the Honeywell valve actuates the spindle and the arm starts moving back to AUTO. Any more obvious hints tips? Trying not to resort to calling out Dick Turpin, especially with Santa coming soon. Thanks.