I'll provide as much info as i can, I'm not a plumber or heating engineer by a long shot, give me a car to service or maybe some car electrics i'm ok....
Anyhow, I'm ok with spanner and some tools as long as nothing gas related doesn't come up, that scares me!
Everything was working fine up untill last week, then the water decided to just get warm rather than hot, there has been the odd rush of hot water but only for seconds other than that its just over luke warm, i took the rubber diaphram out of the actuator as this has been mentioned a few places on google etc etc. I held it up to the light and checked for any splits there doesn't seem to be any, before i put this back together i cleaned the slide and oiled it so the pin can move freely, then i had cold water for a while, I think this is maybe from turning everything off and getting rid of airlocks etc??? Then back to getting just warm water again, there is what appears to be copper rot around the one temp sensor near to the actuator but that is for the heating???
Any help apprieciated and i'll check what I can without taking anything direct to the gas appart, the gas lights when the tap is turned on whether the heating is on or not too, that seems to be the most common fault, why can't i just get the most common fault!!! lol