Power shower pump coming on when taps turned off???

hi, need some plumbing help. My power shower was playing up nearly a year ago and it finaly give up the ghost. So i purchesed a new pump and it seemed to work.

But now it's starting to play up again. When you turn the hot water tap of any where in the house you can hear the pump starting for about 1/2 a second if even.

Also sometimes it plays up when your gettinga shower too, going from hot to cold??? For some reason it seems to be worse when the heating been on for a while.

Need some help with this before the new pumo goes as well.

Any ideas??

hows the hot for the pump connected to the cylinder ?
is it taken from the the dhw supply pipe ?

Hi seco services, bit clueless about plumbing but yes i think the pump is connected to the cylinder by the dhw supply

what pump/model is it ?
are they 15mm feeds to pump or 22mm ?

you'll be better fitting a surrey or essex fange to the cylinder to supply hot water.
whats the cylinder stat set to temp wise ?

Hey sorry for not getting back been busy with work over the weekend, the pump is a showerforce easiboost. It's was just a cheap buy as our house is upfor sale and didn't want to spend lots.

As for the feed do you mean the inner or other size of the pipe? Looks about 22

The stat was turn fully up, since then i've turned it down and seems ok so far. Only thing is the hot water just doesn't seem hot enough. I've turned it up a bit eat nite and now this the water's how enought and has stopped playing up so far. Could this have bee part of it?

Whats a surrey or essex fange and what do they do??