Shower Pump Vs Electric Shower

Astilbe

I've been reading up a lot about the pros and cons of installing a shower pump or an electric shower.

Currently we have a mixer shower with poor hot water pressure. The water tank is in the attic, the immersion is on the ground floor and the bathroom (where the shower is) is on the first floor.

We have had some plumbers out to have a look at this and have learnt that our bathroom cold water is mains fed!

One plumber said that this was a problem and that we should re-do all the plumbing in the house including installing a pump beside the immersion to boost the water pressure.

The other plumber said that the bathroom cold water being mains fed is common in old houses and that we should leave it, that all we needed is a new shower...

I've been reading about pumped electric showers and the first warning on them is that it should not be connected to the mains, but instead to gravity fed cold water tank.

Has anyone come across this situation before? Any thoughts?

John T Carroll

Astilbe wrote: »

I've been reading up a lot about the pros and cons of installing a shower pump or an electric shower.

Currently we have a mixer shower with poor hot water pressure. The water tank is in the attic, the immersion is on the ground floor and the bathroom (where the shower is) is on the first floor.

We have had some plumbers out to have a look at this and have learnt that our bathroom cold water is mains fed!

One plumber said that this was a problem and that we should re-do all the plumbing in the house including installing a pump beside the immersion to boost the water pressure.

The other plumber said that the bathroom cold water being mains fed is common in old houses and that we should leave it, that all we needed is a new shower...

I've been reading about pumped electric showers and the first warning on them is that it should not be connected to the mains, but instead to gravity fed cold water tank.

Has anyone come across this situation before? Any thoughts?

In view of the fact that you had a form of power shower although with very poor pressure, you might prefer to stay with that arrangement rather than a full electric shower which will require 40 Amps & 10 M2 cabling to run it and it will still only give around 3.5 LPM. If the only requirement for increased water pressure is for showering purposes then you can install a power shower with a integral pump like a Triton AS2000XT which will need 2 X 1/2 ins water supplies, the cold from the header tank and the hot from the your already existing shower hot water supply so you would only need to run a new 1/2 ins cold water supply OR you might find it convenient to connect (convert) your mains bathroom supply to the cold from your header tank, you often find that these are running side by side and are very easy to switch over. Because this shower is not heating the water it only needs a amp or so (100 to 150 watts) to drive the pump and will supply up to 14 LPM of hot water, the hot water supply is really only limited by the size of the hot water cylinder. You speak of the "immersion", I assume you have another means of heating the hot water ie a oil fired boiler coil in the cylinder?.

Astilbe

John T Carroll wrote: »

You speak of the "immersion", I assume you have another means of heating the hot water ie a oil fired boiler coil in the cylinder?.

We have a cylinder with immersion switch (electric) and Gas central heating which heats the water in the cylinder too.

Would installing a pump that would boost the hot water supply avoid having to plumb in a cold water feed from the attic tank? I'm thinking of cost and disruption to our current bathroom...

Thanks for your detailed response!

John T Carroll

Astilbe wrote: »

We have a cylinder with immersion switch (electric) and Gas central heating which heats the water in the cylinder too.

Would installing a pump that would boost the hot water supply avoid having to plumb in a cold water feed from the attic tank? I'm thinking of cost and disruption to our current bathroom...

Thanks for your detailed response!

If you don't want any disruption whatsoever then you can install a booster pump that will only boost the hot water pressure, your plumber would have to look at this very carefully as you would be boosting the hot water coming out of the cylinder, I don't know how well that would work if you are boosting the whole house hot water, you could just consider just boosting the hot water supply to the shower/bathroom taps, you will also have to have a good idea as to what the cold water mains pressure is as the boosted hot water pressure should match this as closely as possible, I would advise monitoring the mains pressure by getting a pressure gauge fitted before making any decision. If you go down that route I would also advise getting a thermostatic mixer fitted to your shower (if not already fitted) as you really have no control over the mains pressure. Here is an example of one of these "single" booster pumps... http://www.stuart-turner.co.uk/products/monsoon/s20-bar-single/

or this one for the shower only.... http://www.stuart-turner.co.uk/products/showermate/u26-bar-single/

Astilbe

Thanks again John, that's great information to have.

I'll have a look at the mains pressure and then decide if a single pump will be suitable (our mixer is a thermostatic).

Accessing pipe work to hook up a cold feed from the header tank will most likely involve ripping out parts of the bathroom walls and the bath, so if it comes to it we would probably be as well getting a new bathroom altogether!

Either way, I want a shower that works properly so will have a good think about the options.

John T Carroll

Astilbe wrote: »

Either way, I want a shower that works properly so will have a good think about the options.

A mixture shower will obviously only operate (mix) at the lowest pressure available from either the hot or cold water and that's the reason that a hot water head of say 3 meters (0.3 Bar) will result in such poor performance irrespective of the cold mains pressure. If you find that the mains pressure is say 1.5 Bar then you can select a (hot water) booster pump to be = or greater than this at say a hot water flow of 7 LPM which would give a combined flow of ~ 10 LPM at 43C. If your actual original head was 0.3 Bar (you can measure the height) then the flowrate (at 1.5 Bar) will be over 2.2 times that at 0.3 Bar, Sq.root(1.5/0.3). 2 Bar pressure would give over 2.5 times etc. so thats why its important to monitor that mains pressure, in my opinion.

Astilbe

Just wanted to give an update in case it's helpful to anyone else in a similar situation.

I measured our mains pressure and it was well above 4Bar at all times of the day so decided to go for a pump to improve the hot water pressure.

After a bit of messing from various tradesmen (no-shows, insisting an electric shower would be best etc.) we finally got a pump installed. As it turned out, there was no dedicated overflow pipe so the plumber installed a new one for us- and now we have a shower with decent pressure! I'm delighted!

The pipes in our house seem to be a mess and should be redone altogether in the near future. In the meantime this will do!

Thanks again John T for your advice on the matter!