shower pumps

[iannegus]

Hello

My parents have recently moved into a bungalow. There is a thermostatic shower installed. The problem is there is a single pump in the loft for a dedicated cold water line and there is a single pump tee'd off the hwc hot pipe. These both work ok only when you start mixing the shower they start surging. Is this because the pumps are in different places and not getting equal pressure? Thankyou in advance for any advice

 

[jam1979]

Are the pumps the same

 

[jam1979]

Could be dragging air in depends where it's tee d of the hot

 

[SimonG]

Both hot and cold fed from same tank, if not are both tanks at same height?

Have you stripped the shower and cleaned any filters?

Does the shower have integral check valves? Are they working correctly?

Ideally it would be better to have a twin impellor pump.

 

[jam1979]

Could be dragging air in depends where it's tee d of the hot

 

[jam1979]

Forget that last post l o l