I have a strange problem in that my central heating keeps switching itself off. I have a programmer on the boiler and remote thermostat. The programmer allows for on, off, once and timed but quite often recently when the CH green light flashes and the burner will not ignite. The programmer shows the heating is switched off. Pressing the select button to try any other option does not work. However if I press the 'OK' button the indicator moves to 'on' (but not to either 'timed' or 'once') and the burner ignites. After a short period (minutes rather than seconds) the indicator switches from 'on' to 'timed' by itself. At the moment the heating stays on more often than not until the end of the timed period and then the CH light goes out and the programme indicator shows 'off'. I have replaced the batteries in the remote thermostat. The water heater works perfectly. When I turn the hot tap on the burner light comes on and if I try to switch the heating to 'on' or 'timed' whilst the hot water is flowing the heating comes on until I turn the tap off and then the burner light goes off with 10 seconds and the heating shows 'off'.
Any help would be very much appreciated.
Any help would be very much appreciated.