I have just had a new bathroom fitted. I have a separate shower unit (which I had in the last bathroom) this was power by a twin impeller pump, which is in the loft and the water comes from the cold water tank (located in loft) and hot water tank (located on same level as shower). My old bath and sink had the cold water coming from the mains and hot from the tank.
After having the new suite fitted the hot water pressure was far to low on the sink, bath and shower was just a trickle. My plumber suggested a single hot water impeller pump located next to the hot water cylinder which was installed and gives great hot water pressure to the bath, sink and shower. The shower would only stay hot though, so he installed a single impeller pump in the loft for the cold water to the shower only, which gives great pressure to the shower, HOWEVER......a problem occurs when he tried to mix the temperatures. One pump seems to switch the other off to there is a toing a throwing of pumps making the water flow very uneven, i.e hot - cold - hot - cold, you can hear the pumps shutting on and off in turn.
does anyone have any idea's of how I can achieve equal balance for the shower?
I have a thermostatic shower valve, the hot water pump is 1.5 bar 22mm, the cold is 1.7 bar 15mm. The plumber has suggested either trying the cold water coming directly from the cold tank, or mains.
If anyone can suggest and advice I would really appreciate it, I am so worried that the bathroom I have spent a lot of money on will not have a decent working shower.
Thanks,
Mike