I’ve got a 7 year old Valiant combination boiler. The heating is working perfectly but the hot water has packed up. When I turn on the hot tap (the pressure is v. good) the gas lights and immediately cuts out, the gas comes back on and cuts out …. this continues until I turn the tap off. I’ve had the engineer (who usually services the boiler) around to try and fix the problem and after scratching his head for a while he replaced the controlling circuit board. This fixed the problem for a day but I have only been able to get hot water on 2 days in the following three weeks.
I understand that their is a controller value that will cut off the gas if the water pressure drops to danger levels. Is it possible that this could have failed or be mall-functioning?
At the moment I have shelled out £170 pounds to replace a component that was probably sound and am no better off.
I’d be grateful for any ideas as I have the engineer coming back next Monday.