Valliant boiler seems to be making all the right noises and there are no issues with the heating. 2 of the pipes leading into / out of the boiler are hot, indicating hot water, but the water coming from the taps is cold. Does anyone know why? The same thing happened before and the problem just sorted itself out. Any suggestions?

Paul, March 2008

divertor valve is in ch position. when you're demanding hw the boiler fires up but whacks the heat straight down the ch system. one way to generally get an idea is.

allow heating to cool totally all cold pipework under boiler. generally heating flow and return and most of the times gas will be 22mm pipes where cold supply and hw out will generally be 15mm.

run hot tap and feel which pipes get warm and hot. if it is like i think, one 15mm pipe will get warm and 22mm will get red hot indicating heat is being lost through ch side instead of dhw.

iain, March 2008