Install a shower pump above HW Cylinder But below CW Storage

20 Jan 2016
Reaction score
Sutton Coldfield
United Kingdom
Just as a quick sketch is this possible?

I would like to install a shower pump in my airing cupboard, due to space I cannot fit it below the cylinder, only on a shelf above. I would have 700mm of static head between the cold water storage lowest position and the pump. The shower head would be 400mm above the shower pump.


Sponsored Links
Most pumps ask for a considerably higher static head.

But it is not the static head that matters as it is the dynamic head and I would expect you to have problems which the makers will not be interested in as it is installed contrary to their requirements.

I also expect the cold feed to your cylinder may be undersized?

Right, OK.

I am struggling to find anywhere to fit a positive head pump in. Cant fit under floorboards, cant fit at the base on the HW cylinder, freestanding bath so cannot hide behind a bath panel.


Could I fit a negative head pump in the loft? This would be on the same level as the cold water storage tank.
Sponsored Links
Others will comment on negative head pumps but I am not confident they will be your solution.

A common solution to your problem is to raise the cylinder by about 400 mm and fit the shower pump underneath.

You'd be better off with a Universal pump than an positive head one, but whichever one you choose (my preference is Stuart Turner Monsoon) you'll need to ensure it's fitted to manufacturers' instructions or it won't be covered in the event of premature failure
A common solution to your problem is to raise the cylinder by about 400 mm and fit the shower pump underneath
Why raise the HW cylinder?..what difference would it make to site the pump on floor next to HW cylinder?
No reason whatsoever to raise HW cylinder..:rolleyes:
Raise the cold water storage tank higher and fit the pump above the cylinder, make sure all piped correctly and it will work.

I must be missing something here, there is 700mm between the cold water cistern and the pump so satisfies the min static head requirement so no need to raise the cold water cistern, a negative head pump would be needed and would be easier than raising the hot water cylinder.
The important dimension is that from the surface of the water in the cold tank to the pump inlet. That is the head dimension that must be met.
It matters not where the bottom of either tank is as long as there is a head difference as I have defined it.
Cold tanks can become depleted during use with a pump so the static head to the base of the tank should be used as the design figure.
Does not matter where you measure from in this case, there is still more than enough static head to meet the minimum.

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local

Sponsored Links