Phil L wrote:

Existing kitchen gravity HW feed that came from top of 4 year old HW
cylinder (in airing cupboard upstairs) is now fed from the outlet of
the pump (also in airing cupboard) which is a 22mm feed from the side
of the cylinder. The cold water tank (softened water) is on a raised
platform in the loft and feeds the cylinder using 28mm pipework.
Reason for pumping kitchen circuit was to increase flow (which it
does) and try and get over the lag which is now worse

'lag' as you call it can only be air getting into the system.
When yoiu turn the tap on, can you hear air being forced out prior to the hw
appearing? - what happens if you put your finger over the tap before turning
it on? try it and let us know


Tried that .. no air being expelled. It can only be insufficient water
pressure to operate the ceramic valve although it does eventually come on.