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Choosing the Right Product

If you suffer from poor water pressure and flow in your home one of our products can often be the perfect solution. The results are; improved shower performance, quicker bath fill and strong flowing taps. However, it is important to make sure that you get the right product for your heating system.

What system do I have?

The first step in finding the right pump for the system is to determine what type of system the property has. Below are three images to demonstrate the three main system types in the UK.

Illustration showing a gravity system

Gravity fed

If you live in an older property there’s a good chance you have a gravity fed system, renowned for poor pressure and flow.

Find out more

Illustration showing a combi mains system

Mains fed: Combi boiler

Combination boilers are common and rely solely on mains pressure to deliver water around your home.

Find out more

Illustration showing an unvented system

Mains fed: Unvented

Unvented systems require a separate hot water cylinder to store a quantity of hot water at mains pressure.

Find out more

Gravity fed system

The video on the right explains how to identify a gravity fed system.

Gravity fed systems are still widely used in homes across the UK, they rely on gravity to push water around the system, which often isn’t forceful enough for powerful showers or flowing taps. That’s where our pumps can help.

Salamander Pumps manufacture a range of products suitable for gravity-fed systems, including CT Xtra, CT Force, CT Bathroom and Right Pumps.

It is important to choose the right pump for your system as incorrect selection can lead to the pump not working. To decide which option is best consider the sections below.

Gravity fed system identification

How to Identify a Gravity Fed System

Do I need a positive head or negative head pump?

A gravity-fed system is either positive or negative head.

A positive head pump will only work in a positive head system.

A universal (negative head) pump works in both positive and negative head systems. So if you’re not sure choose a universal (negative head pump.

The video to the right explains the differences between a positive head and universal (negative head) pump in more detail.

Read on to find out how to check if you need a positive or universal (negative head) pump –

Positive and Negative head systems

What are the Differences Between Positive and Negative Head Systems?

How to check if your system is suitable for a positive head pump?

A positive head pump is a flow activated pump.

Flow activated pumps will turn on when they sense the minimum flow of water passing through the pump and out of a pumped outlet, such as a shower or tap.

The minimum flow is the natural flow rate required to turn on a positive head pump. Natural means without assistance from the pump.

The minimum flow rate required for our positive head pumps is 2 litres of water per minute (L/min), the video on the right shows what this flow rate looks like from a tap.

How to Measure Your Water Flow

Carry out the following test to determine if a positive head pump is suitable for your system. You will need to test all outlets, such as showers and taps, that are going to be pumped to determine if they have the required minimum flow rate.

For showers and mixed hot and cold taps –

  1. Turn the water to fully hot.
  2. Time how long it takes to get 1 litre of water, if it takes less than 30 seconds then its positive head.
  3. Repeat the process for fully cold – both hot and cold must get 1 litre of water in less than 30 seconds for the system to be suitable for positive head pumps.
  4. For showers, you also need to get 2 litres of mixed water (hot and cold together) in 30 seconds.

For hot or cold outlets, such as a hot or cold tap –

  1. Time how long it takes to get 1 litre of water, if it takes less than 30 seconds then its positive head

Use our interactive flow calculator to calculate the flow rate of a single outlet.

If you cannot measure the water flow rate, then you can check if the system is suitable for a positive head pump if there is more than 600mm between the base of the cold-water storage tank and the highest point in the system after the pump.

The illustration to the right shows a pumped shower in a gravity fed system, with the dotted line indicating the point 600mm below the cold-water storage tank. The highest point in the system is the top of the shower, we can see that this is below the dotted line and is therefore suitable for a positive head pump.

If you are unable to achieve the minimum flow rate of 1 litre per 30 seconds from all outlets that are to be pumped you will need to install a negative (universal) head pump.

An illustration showing what a Positive Head is

What do I want to pump to?

You need to work out whether you want to pump to the shower only or additional appliances, for example bath taps, the toilet cistern or washing machine. The CT Xtra twin range will pump the shower only, all other ranges are suitable for multiple household appliances. View our shower pump selector guide below for further information.

Do you want to boost hot AND cold water or hot OR cold water?

Hot AND cold water

In cases where both hot and cold water are to be boosted a twin pump is needed. Twin pumps have two impellers, one at each end of the pump, one for hot water and the other for cold water.

Hot OR cold water

In cases where either the hot or cold water is to be boosted a single pump is needed. A single pump only has one impeller which can be connected to either the hot or cold water supply.

What bar rating do I need?

Selecting the right bar pump for you involves considering the size of your shower head and how many outlets you want to pump to. View our shower pump selector guide below for further information.

Shower pump selector guide:

Below is a guide to determine what pressure/bar pump you’ll need to boost the water in your home. Once confirmed you can then select which pump range you prefer:

For installations where both the hot AND cold water are to be boosted (requiring a twin pump):

I want to boost:Pressure/Bar rating required:
Shower ONLY with a shower head of 100-120mm.1.5 Bar
Small bathroom and a shower with a shower head of 100-120mm.2.0 Bar
Larger bathroom or multiple smaller bathrooms with a shower head of 120mm+.2.0 Bar
Multiple bathrooms, 150mm+ shower heads and/or shower with massage function and body jets.3.0 Bar

Where pumped water meets mains-fed water the selected pump should match the mains pressure as closely as possible – you can either choose a pump which meets the mains pressure as close as possible or use a pressure reducing valve to lower the mains pressure, being mindful of the shower head size.

This would occur in installations such as:

  • When a whole house pump has been installed to boost all outlets across the home, and at the kitchen sink the hot water is boosted by the pump but the cold water is supplied from the mains,
  • When a pump has been installed to boost only the hot water to a shower, which is supplied by mains fed cold water.

Anywhere pumped hot water meets mains fed cold water, a negative head pump should be used.

Which pump range should I choose?

The CT Range of shower pumps have a regenerative impeller. They are long-lasting, hardworking, compact, and easy to install.

CT Xtra pumps are suitable for positive head installations and are available in 1.5 or 2.0 bar.

CT Bathroom pumps have been designed specifically to meet the demand for increased water supply to the bathroom.  With positive head and negative (universal) head models available in 1.8 or 2.6

CT Force pumps have robust brass ends and brass impellers, and the range includes positive and negative (universal) pumps. Suitable for boosting the shower, bathroom, and whole house. The products in this range include a 5 year warranty and are available in 1.5, 2.0 or 3.0 bar.

The Right Pump range of shower pumps have a centrifugal impeller, making these pumps very quiet and allows them to offer maintained pressure at increased flow rates. Suitable for boosting the shower, bathroom, and whole house, available in positive and negative (universal), and up to 3.0 bar pressure.

Mains fed heating system: combination boiler

If you have a combi boiler in your home your system is mains fed and relies on the local water authorities to provide water to your property boundary. This means that your water pressure and flow may vary at different times of day e.g.. when your neighbours are also using water too, or you may constantly have less water pressure and flow than you would like. Salamander Pumps offer a range of mains booster products including inline pumps and accumulator tanks to improve mains water pressure and flow in domestic and light commercial installations.

Inline Pumps are quiet, compact and easy to install. CombiBoost will boost mains water flow up to 10 litres per minute. HomeBoost is an intelligent inline pump, it recognises when mains water pressure and flow are low and automatically boosts the flow up to 12 litres per minute. This improves shower performance and allows for stronger flowing taps and quicker bath-fill

Accumulator Vessels can offer even more flow than an inline pump, providing an additional flow rate up to 24 litres per minute. The AccuBoost range of accumulator tanks store water at pressure in the vessel and release this water into the system when there is demand in the property. They are available in a range of different tanks sizes, depending on your requirements, how many outlets you want to run at once and what space you have available in the property. Selected models will fit into a standard kitchen cupboard. Choose AccuBoost accumulators when your mains flow is more than 9 l/min and pressure is 2.0 bar.

TankBoost is a great solution for a larger properties. It is an all-in-one unit made up of a water storage tank and an integrated submerged pump. Additional cold water storage is boosted by an integral submersible pump to increase both pressure and flow, delivering up to 3.0 Bar and 80L/min.

Link multiple tanks together to increase performance.

Better shower performance Salamander Pumps

MainsBooster Range Overview

Mains fed heating system: unvented

AccuBoost Accumulator Vessels

AccuBoost offers a range of accumulator vessels suitable for boosting mains water performance in an unvented system to provide better pressure and flow to your shower(s), bath, basins, taps and toilet. Water is stored at pressure within the vessel and released when there is demand within the property. The AccuBoost 330 or the AccuBoost 450 are recommended to deliver the required flow rates.


TankBoost is the newest range from Salamander Pumps providing higher water flow rates than any other solution in our portfolio. Delivering up to 3.0 Bar and 80L/min, TankBoost will boost multiple outlets, across multiple floors, all at the same time, in a mains-fed system.

Choose TankBoost for a busy home, or when you need to boost water to multiple floors to achieve that enhanced shower performance, even when other outlets are running at the same time.

Link multiple tanks together to increase performance, additional tanks added must be the same size as the main pumped unit.

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