pipe size question - Plumbing Forum | Plumbers Forums

Matty A · 30-09-2007

On a gravity fed system would it make a lot of difference to the flow pressure to the bath taps if the pipes where reduced from 22 to 15 for the last meter or so?

Also is there any way of increasing the pressure to both hot a cold feeds with out the use of a pump as i have a customer who complained of the reduced water flow to her bath hot water so i suggested putting in a single end shower pump which i installed on friday she is now saying the pump is too noisey and wants it out but i should also add that she has a fancie shower with normal shower head and one of those large rose thingies which she got off EBAY.

The pump fitted is the Techflow QT-45..

**uug197h** · 01-10-2007

its better to have 22mm mpipe to the bath taps, where did you put the pump????????, the shower sounds like a diverter valve and would be better if it was used with a combi boiler, it may use more water than a gravity can supply

Matty A · 02-10-2007

Cheers for that mate i sorted it today i up graded the pump to a twin impellor and boosted both hot and cold.
I put the pump infront of the cylinder in airing cupboard and it has its own seperate feeds both hot and cold this has worked fine. As for the noise it was just vibration which i sorted with some loft insulation taped to a piece a ply and placed under the pump.

I also changed the bath taps back to 22mm it has made a little difference but not much.

SteveO · 19-02-2008

Ah man I have just sorted out this type of thing.... well what someone else had messed up anyway.

Here is my advise....

Firstly you should in my experience us a twin impeller pump as you have done. However, you should always read the manufacturers instructions BEFORE installing the pump. Mostly you will find that the pump must be located next to the DHW tank, connecting via either a surrey or essex flange on the tank.... as per the install instructions. The reason for this is that it will not then void the manufcturers warranty.

It sounds like you have the pump mounted in the roof space and it is/was sitting on the loft boards... therefore creating far too much noise...

Really the pumps sould be located next to the DHW tank and running the suggested "at least" pipe size according to the install instructions etc etc.

Hope that helps