when i turn the hot water on the boiler lockout. when i turn heating on its ok and then i can turn the hot water on and get hot water. i can only get hot water when the heating is on .
soundslike you need a new diaphragm in you flow switch these wear and so don't sense the hot water moving hence boiler doesnt light. get your gc no. off the boiler to orderareplacement if you feel confident enough in changing it.....