I am having trouble with my boiler. The plumber has just says that it is the diverter valve and is taking forever to get a price on one. I have checked the manual and also this website but still need some help. This is what happens. Turn on hot tap and after a couple of seconds the bolier fires up. The water becomes luke warm and then after about 30 seconds the pilot light goes out and then comes back on a few seconds later, hense no hot water. I have read the different posts saying that it might be the diaphragm but the small piston is coming out as it should. Please can someone help. Cheers