The diapraghm is located in the divertor valve assembly behind the plate heat exchanger (a big rectangular ish silver thing. to get to the diapraghm you will need to remove the charging link assembly, the plate heat exchanger and half the skin of your knuckles. the diapraghm can be changed in situ, its a bit fiddly (the 2 securing nut at the back) but it can be done, dont forget to electricaly isolate the boiler, turn of the cold water and drain the central heating water.
P D, August 2007
