Power Shower - a new issue

[glynnw]

Aqualisa 3TE pump running from CWST and HWC has suddenly developed reduced pressure flow at shower head.
HWC very hot to touch at top, cold at bottom (once hot water used)
Have tried removing airlock by hot-cod-hot "bleeding" as suggested by Aqualisa. Problem returns though.
I have no control over HWC temperature - is this my problem?

 

[seco services]

useally bad pipe design. and to hot don't help

 

[glynnw]

thanks - but system has been perfect for 12mths
why now, could it be my water heating is on too long as recently fiddled with my central heating

 

[seco services]

have you checked the filters on the pump ?