i went to a job were the immersion keep't blown,so the idea was to change it, not just the element the whole immersion, any ways the bloody thing would not budge and the cylinder started to buckle,meaning a new cylinder but when i looked at the cylinder there was two tappings on the side, but this house has no central heating and according to the house owner there is no back boiler,so this has got me wondering were these two 22mm pipes go,by the way they have no vent or cold feed and no tank in loft,could they be when house had a solid fuel fire some kind of heat exchanger,another thing what is the best solution for changing from imperial to metric pipe sizes