Pump for Shower

[Tim Brennan]

At home all our water upstairs (both hot and cold) is fed by the water tank in the loft and our water pressure is pretty low.

About 10 years ago we installed a shower with a thermostatic valve, but unfortunately the pressure is not sufficient to ever use it. So instead, we have been using a shower that fits over the bath taps. It is no power shower but is good enough.

The downside of this solution is that every 5 years the rubber perishes and it no longer wants to stay attached to the taps, additionally the flow is still a bit low and it is really an optimal solution both visually and practically.

I had a quote for £500 many years ago for fitting a pump to fix this. My questions are 1. How long do these pumps last? 2. are they costly to maintain? 3. Is there a particular brand or model to go for? 4. Are they noisy? 5. Is it best to install in the loft which is unheated to keep noise to a minimum or will that cause problems with freezing in the winter? 6. I'd like to be able to control the flow of water but the pumps I have seen don't seem to have any settings to control the output. What can be done to control the water flow rate?

 

[Roseland]

Unless you have very low water pressure on the cold supply, you could consider an unvented hot water cylinder, like a Megaflo:https://www.heatraesadia.com/products/cylinders-and-hot-water/unvented-cylinders

Both hot and cold are then delivered at the taps at essentially the same pressure, which assists thermostatic valves in keeping a steady temperature.  Other advantages are that you do away with the header tank, and its associated risk of leaks, and save loft space.  They are also silent, and require no wiring.

My experience with pumps in three properties have all been disappointing; they don't seem to give the boost the brochures promise.

Good luck.

Andrew

 

[AstroKeith]

I'll put in a vote for a pump!

I have retro installed two so far. My own is now ten years old and no problems. Really does boost pressure! Now my wife can empty the hot tank in one long shower.

Yes they can be a bit noisy. I've put them in the loft, but under a well insulated cover and no insulation underneath. Then used plastic pipe to rescue noise conduction.

A good pump (Salamander or Grundfoss) will cost less than £150 (eg Screwfix). The hot feed to the pump needs to come from the top of the hot tank so a bit of work there(Surrey outlet flange £25). Assuming your shower installation is still OK its just down to running pipes. £500 seems a bit steep, but then I'm happy to do my own plumbing!

 

[DeformedTree]

So, I would think you don't want "a pump" but you want to have things set up like you would on a well, with a pressure tank, and a pump that pumps that up.  It kicks on when the pressure drops and refills.  A well system inside the house.

 

[DeformedTree]

So... this will be a Europe vs N. America question.

Unvented Cylinder looks like a odd way to say "tanked water heater"?  Am I missing something?  One thing I found acts like they are a wonder device and made legal 30 years ago.  Here, we are slowly getting rid of tanked heaters for tankless.  But it's not clear what a "vented Cylinder" is,  stuff is taking about gravity, and having full mains pressure with an unvented cylinder?  How do you guys make hot water? 

Even with Tankless, we just supply it from the main.  If you want to lesson the power draw, you put a tank in front of it that absorbs heat around it to get to room temp, but this is still all air mains pressure.

 

[Bohdan]

At home all our water upstairs (both hot and cold) is fed by the water tank in the loft and our water pressure is pretty low.

This suggests that you have a gravity fed system with both the hot and cold fed under gravity to enable you to set the temperature easily.

You cannot fit a pump to the cold water input side of your hot water as it would flow out of the vent and if you block the vent the pressure would probably burst your tank.

If you fit a pump on the hot outlet of the tank you will get lots of hot water but the cold would not be able to keep up. The solution would be to fit another pump to the cold side (starting to get expensive) or see if you can replumb the cold to run straight off the mains.

If you do fit a pump to the hot side make sure that it is not one of those cheap plastic impeller ones as they cannot handle the hot water.

If it was my problem I would look at replacing the hot water system with a mains pressure one and all your problems would go away.

 

[AstroKeith]

Pump showers in the UK have two channels/impellers, one for hot one for cold. They have auto sensing switches so they come on when you turn the shower on. Honestly this isn't difficult.

 

[Tim Brennan]

Unless you have very low water pressure on the cold supply, you could consider an unvented hot water cylinder, like a Megaflo:https://www.heatraesadia.com/products/cylinders-and-hot-water/unvented-cylinders

My experience with pumps in three properties have all been disappointing; they don't seem to give the boost the brochures promise.

Good luck.

Andrew

The local water board turned down our water pressure a few years back when there was a mains leak in the street. It was very high and now it is very low - about 1 bar or so. I guess that rules out the megaflo?

 

[Roseland]

1 bar is quite low; it will give you a head equivalent to having the tank 32 feet up from where the pressure was measured.

Megaflos have a regulator to stop over pressure (you really don't want the tank to burst!) and this is I believe set to 3 bar.

I think I'd ask a plumber you trust and maybe neighbours to see how others have addressed the problem.

With 3 bar (as we have downstream of the regulator) I can have water hotter than I want and at a pressure that hurts, but I can't comment in 1 bar.

This might help:
http://www.megaflo-unvented.co.uk/megaflo-installation.php

Andrew