... after replacing the diverter valve diaphragm, dhw heat exchanger and cleaning the inline filter I'm still left with one problem; low dhw pressure so that when any other tap or appliance is turned on at the same time a hot tap is on, the boiler stops heating the water. Is there any way of increasing the flow rate on the dhw circuit?? any help very much appreciated.

Paul K, June 2008

you would first need to establish what your mains water pressure is (at the lowest) and ensure it is above what the boiler manufacturer recommends.

If it's below this, you will beed to get someone in to install a feeder tank for the boiler to ensure enough constant pressure

T, June 2008