I have a Chaffoteaux Britony !!A water heater and the diaphragm has split preventing the water pressure operating the gas jets to heat the water. Last time this happened a plumber quickly fitted the diaphragm while I switched the water off. I can't remember now how he fitted it so quickly without undoing all the various nuts & screws as it was several years ago. I have bought a new diaphragm (no easy task). Does anyone know how to fit it quickly?

there is no easy way to change one of these and furthermore only a gas safe engineer will be able to carry out the work, if you get stuck visit http://www.plymouth-plumbers.co.uk and they will be able to help