hi the pressure on my 28cdi has gone up to 3 bar.
i think it might be the pressure vessel or the water to water heat exchanger..
how would i test to see which is faulty

paulcfc, December 2008

thanks for your quick reply steve,,,
i will try that in morning ,,,,

thanks

paulcfc, December 2008

Drain down the system to 1 bar and with the boiler switched off there should be no increase in pressure if there is then its he water to water heat exchanger.
Again with the boiler at 1 bar pressure run it in CH mode there may be a small rise in pressure .2 to .5,A steady rise in pressure would indicate a blockage,deflated faulty pressure vessel

justeve, December 2008