Shower pump cuts in when bathromm tap is turned off

[cj.wheeler1]

I have a shower mate pump for a gravity system feeding a mixer shower. Recently the pump has started cutting in briefly when I turn off the bathroom tap.

Any suggestions what might be causing this or how to fix it?

Thanks

 

[londonboy123]

what do you mean the bathroom tap? on where the bath/basin?

 

[cj.wheeler1]

The problem is with the the cold tap in the basin.

The pump directly feeds two showers and does not feed any other taps etc.

 

[seco services]

we need more info on how the pump is plumbed in.
is the cold run from the cws in loft?
is the cold for the pump teed of this pipe or straight from the tank?

 

[cj.wheeler1]

Cold feed is from cold water tank in loft. Hot is from hot water cylinder in airing cupboard. Pump is in bottom of airing cupboard

 

[seco services]

so where is the cold to the tap from direct to the tank or teed of the other cold ?

 

[cj.wheeler1]

I think the cold to the tap is teed off another cold rather than direct from the tank