These days there is very little that can stop the determined person from enjoying a good powerful flow of water wherever they want within the household. Modern water pumps can be strong but unobtrusive and can provide great flexibility of operation.
The most common application is to boost a feeble or otherwise-impossible shower flow: but in many instances the pump can handle all the water in the house, raising an inadequate pressure to the necessary level.
Depending on your requirements (and you must check with the manufacturers’ specifications before buying) you can use these devices to provide the necessary supply of water to:
- Combi boilers
- Instant electric showers
- Instant water heaters
- Washing Machines
- Washbasins (hot and cold supply)
- Baths (hot and cold supply)
All these, as well as the various types of shower. Again, before deciding on your pump, check whether it can handle the differing types that are popular now, which may include:
- Body jets
- Champagne spray
- Massage jets
- Victorian ‘can’ shower head
A shower pump is best left to the professionals when it comes to installation. But before you let someone talk you into the wrong, or over-specified, unit, it helps to have a basic idea of the types available, which are many and varied. These are some of the key differences between them.
Are you Positive or Negative?
It’s not about your state of mind: it is a question of whether the unit in question lies below the level of the cold water tank. If this is so, and you have a hot and cold vented system, and subject to there being a minimum level of pressure in the supply (as specified by the makers), then you can use a ‘positive head’ system. This is a bit simpler and tends to be a bit cheaper than the alternative.
Which is the ‘negative head’ system. These are usable where you do not fulfil the above criteria, not requiring a gravity flow. Many are fully automatic and allow fitting in any circumstance.
Do you need a Boost?
Units, whether positive or negative, are also classified by their output. These are broadly banded as follows:
Up to 1.0 Bar = low boost
1.0 to 2.0 Bar = medium boost
2.0 to 3.0 Bar = high boost
Size of boost isn’t everything: a medium boost is often all that is needed to turn a single gravity shower into an invigorating experience.
I feel impelled…
You will also come across ‘single impellers’ (to improve the flow of cold water from the tank) and ‘double impellers’, which are what you use to turn your Victorian-style shower or Continental multi-function unit into a Niagara-style torrent.
Another factor to bear in mind is that you may be dealing with 15mm plumbing. Most of these fancy pumps use push-on 22mm pipes for enhanced oomph: to avoid converters you can buy pumps that use 15mm. Triton is one maker that offers this option. They will not be high-end models but they may suit your needs.
Why so pricey?
As with most engineering, you get what you pay for and often it is the hidden components that make the difference. Opt for the high end and you are likely to get brass components and carbon graphite or silicon carbide seals to ensure a longer, trouble-free operating life.
The impellers and diffusers at the heart of the unit are likely to be superior and will create a bigger splash while splashing out less on electricity.
Above all, when it comes to noise, less costs more. Time and again you will read from customer reviews that cheaper pumps are quite noisy: trade up if you want the ‘whisper quiet’ models that won’t wake the household or the neighbours when you take your dawn shower.
Specific units have their individual advantages. Grundfoss produces a low voltage pump that they call ‘the safest and probably the quietest pump available in the UK’. You can use it under your bath.
This and other high-quality models come with anti-vibration feet that are a major boon in keeping down the decibels.
If you want ultimate power, look at the Stuart Turner Monsoon 4.5 Bar model that can handle a whole house, or power a shower that would satisfy anyone’s need for water speed.
Salamander also offer a wide range including brass-ended models: they claim to be the ‘market leader in shower pumps’. Techflow is another important manufacturer.