I've just added a range with back boiler to my existing central heating system - which is oil fired. Everything runs great until the range gets up to temperature, that's when the water hammer starts. The original piping to the hot water cylinder is 22mm and this is what I've connected the range to. I have since been told that this needs to be replaced with 'inch' piping all the way from the range to the cylinder to solve the noise problem. Is this right or is there any other solution. It's not too big a deal to replace the pipe - but I'd like to know that this is going to sort out the problem... thanks for any suggestions/solutions.