Shower pressure still low after adding shower pump

[barry.haddow]

Hi

We have just installed a pump (1.5 bar, Varispeed 50) to increase the pressure of our shower. However, although the pump does increase the pressure, the change is quite small and the pressure in the shower is still low. The plumber tells us that this is because our pipes are too narrow to feed the pump at a high enough rate. Could this be the explanation? Is there anything else we can try? The pump is positioned less than 1m away from the shower, close to the hot water cylinder. The cold water tank is in the attic.

cheers Barry

[google]

What size are the pipes? The instructions with the pump are usually quite helpfull about sizing and laying out the pipework so as to get the best possible flow.

You did use an appropriate flange to connect to the hot water cyclinder and use a new dedicated pipe from the cold tank with the outlet at the correct height (below the existing one that feeds the hot cyclinder) so that the hot water will always run out _before_ the cold water, rather than just tapping into existing pipework, didn't you?

Andrew

[The Medway Handyman]

Maybe I'm having a blond moment here, but what difference would a dedicated pipe run make to the water flow? I can see the point about the hot running out before the cold, but if you have existing 22mm pipes running to say the bath taps, whats wrong with tapping into them (providing the bath taps remain off of course)?

[Guy King]

The message from "The Medway Handyman" contains these words:

Didn't we do this a while ago? Flow in the pipe dramatically reduces the pressure. Take more from a pipe and the pressure will drop further. For flow-critical devices like showers, take a new pipe right back to the tank.

A few weekends ago we were at a music festival - one long pipe ran round the campsite feeding a dozen or so taps. The few at the far end rarely got any water at all, and then only because the upstream tap users had all gone to bed.

[google]

The real point is that if you don't take a new pipes back to the tanks then you haven't followed the instruction (at least all the instructions I've read for pumps and power showers). So what other bits of the instructions have you also not followed? Pipe sizing, nicely flowed bends, etc? I don't mean you, personally, but the OP.

One very important point is to ensure that the piping is such that the hot water will always run out _before_ the cold.

Andrew

[Ian_m]

Because at least in my last house other things are T'd off before the bath taps (actually also true in my new house as was all obvious when I had the kitchen ceiling down, a 22m feed came from loft tank and hot tank to bath but toilet and bathroom sink were also connected to this 22mm feed) so in my last house someone turns on hot downstairs and you loose hot pressure upstairs in 22mm bath feed.

In my last house a pump was fitted under the bath made a lot of noise but little pressure difference. Also if sink tap was on whilst pump was on, tap sucked in air and you got an even noisier pump and very imtermittant variable temperature shower, quite dangerous really as you would get a hot "spike" before thermostatic valve kicked in and reduced temperature.

Replaced with a proper job, proper 22mm feeds, proper pump (WaterMill), proper valve (Mira Excel) and basically the shower removed the hair off your body if turned on full !!!!

[andyv]

This is to tell you of what happened to me. I had a 1 bar shower pump, but the pressure was pathetic. I switched it to a 3 bar pump and it still wasn't up to much.

I then decided to swap over the mixer unit, and discovered that hidden behind the cover plates on the mixer were two isolating valves. These were almost closed!

I now have a very powerful shower which I have to keep turned down to conserve water.