Do I Need a Shower Pump?

torrent-centrifugal-shower-pump-twin-00026631L

Usually hidden out of sight in an airing cupboard, the humble shower pump is probably the most important item that many people can install in their shower system.

Changing lifestyles have led to a dramatic increase in the demand for powerful showers in recent years. But by no means does every home have a hot and cold water system capable of supplying the large amounts of water at a pressure that a modern shower demands. This is where a shower pump comes into its own.

Keep reading to find out exactly what a shower pump is and whether they are right for your showering needs.

What is a shower pump?

A shower pump is a simple device installed with your shower system to help increase the water pressure and boost both hot and cold water. This then provides an increased water flow to your shower and therefore an overall more satisfying shower experience. Let’s face it, no one wants a shower that feels like drizzle, you want the full rainfall experience.

If you’re not sure if a shower pump is the right option for you keep reading to find out the reasons for installing a shower pump and when they are necessary.

Reasons for a shower pump

Torrent Heavy Duty Brass Shower Pump

One of the main reasons for a shower pump is if your current water system provides only a low water pressure and can’t sustain a powerful water pressure.

A typical British home contains a vented hot water cylinder with a cold cistern tank in the loft. In many cases, there is simply not enough distance in height between the cylinder and the cold water tank to provide enough pressure for that amazing power shower experience.

To run a shower without additional pressure, there has to be a distance of at least 3ft (900mm) between the base of the cold water tank and the shower rose underneath.

Short of installing an unvented, mains pressure cylinder or a combination boiler, both of which can be very expensive changes, the answer for many is a shower pump. Installing a shower pump can raise the water pressure from under 0.3 bar (1.0 bar is the equivalent of 10 metres of head) to up to 3.0 bar.

You need a minimum of 0.5 bar of water pressure for the shower to work properly. And even if you have got this, if the water is turned on somewhere else in the house, your shower could suddenly pour out either freezing cold or scalding hot water.

A shower pump, on the other hand, will deliver water at a consistent flow, pressure, and temperature. It will give you a completely different experience from a gravity-fed system. Without a shower pump, it can be hard to get the mix of hold and cold right in the first place. With a shower pump, showering can literally be a blast.

Get the installation right and showering will be a consistent and luxurious experience with a powerful stream of hot water on demand.

How to tell if you need a shower pump

Salamander CT50 Xtra Twin Impeller

If you don’t want to go crawling about in your loft to find out how much head there is between the cold water tank and where your shower rose might be situated, there is a simple test for determining whether you need a shower pump.

If you have separate taps for hot and cold water on your bath, turn them on as far as they will go and look at the flow of water between the two. The cold will be coming out at mains pressure.

If the flow is equal between the hot and cold, you should be able to install a shower. If, as in most cases with an unvented system the hot flow is much lower than the cold, then you’ll most likely need a shower pump.

What type of pump do you need?

Before purchasing a new pump, you first need to know whether you need a twin or single impeller and whether it needs to be a positive or negative head pump. Keep reading to find out about these features.

Single or twin impeller?

Simply put, a single impeller can only pump one type of water feed; hot, cold, or sometimes mixed. This is used in most cases to pump water to the mixer which already has a cold mains supply. Whereas a twin impeller shower pump or twin shower pump can pump both hot and cold water straight to the mixer resulting in an equal flow.

Negative or positive head?

A negative head shower pump is designed to be used where the outlet for the shower is above the cold-water storage tank outlet. However, a positive head shower pump works when your shower outlet is below your storage tank outlet.

Brass or plastic?

Shower pumps are available in both brass and plastic options but the style you choose generally comes down to personal preference and budget. A brass shower pump tends to have a longer life span than a plastic shower pump due to its high durability, but it does come at a premium. Brass options start from around £233 however, you can find plastic options from as little as £110.

Additional things to consider before buying a shower pump:

There are some other things to consider if you’re thinking about having a shower pump installed:

1) Is your hot water cylinder large enough? Monitor how much hot water your cylinder delivers for a few days. If you have a large bath, see how much hot water you can fill it with before the hot runs out. If it is less than half full before cold starts coming out of the hot tap, you may need a larger cylinder.

2) Consider the size of your cold water ‘header’ tank. With a shower pump, cold water storage capacity is equally as important as hot because the higher pressure pumps deplete water at a rapid rate. As well as mixing with hot water at the mixer in the shower, the cold supply has to replenish the hot water that comes out of the cylinder.

3) Have you got an airing cupboard or another hidey hole to put the shower pump? Although modern pumps are considerably quieter than their older counterparts, they still make a noise and many people choose to put them in a cupboard to dampen the sound, particularly for those wanting a shower early but not wanting to disturb others in the house. There are restrictions around where a pump can be sited in relation to the water pipes and cylinder, but your installer should be able to advise you.

4) Consider the brand of pump. A Stuart Turner shower pump is a great option as is a Grundfos shower pump, or a Salamander shower pump. All are well-known, reliable brands with plenty of shower pump options to choose from.

For more information on shower pumps, take a look at the following posts - What Type of Shower Pump Do I Need? - Common Questions About Shower Pumps - Shower Pumps: Guide to Buying and Fitting.

If you've got your shower and your pump then you may want to take a look at our other ranges of shower enclosures, basins and toilets.


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