Water booster pump buying guide

Parts of a water booster pump

A water booster pump is simply a pump used to increase the water pressure in a system or to keep water pressure constant in your pipes when demand is high. Booster pumps may or may not feature a separate pressure tank but, either way, can be very useful in the home; for example, they can work to sort out any low pressure issues that may occur when using the washing machine and the shower at the same time. Booster pumps turn on and off automatically, or rather a built-in pressure switch detects whenever there is a drop or an increase in pressure and regulates the system accordingly. Pool owners, in particular, can really benefit from high water pressure as pool robots and other pressure cleaning systems are able to remove stubborn dirt much more effectively with good pressure. A pool booster pump can therefore be a great investment.

Surface mounting booster pump

This type of pump system is made up of a surface pump, a pressure tank and a booster pump (which forms part of the surface pump). It is used to draw water from a well or river towards a household to be used for things like flushing the toilet or feeding a garden watering system. This type of system is trickier to choose since it also incorporates a surface pump meaning you'll have to consider factors like discharge height, flow rate and so on.

Advantages of a pressure tank

A pressure tank, which may be referred to as a buffer tank or pressure vessel, is used to store pressurised water. Pressure tanks all vary in volume. The water they contain prevents the water booster pump from having to stop and start constantly. Pressure tanks are all designed for different purposes so be sure to pick the right type for your application.

A booster pump has the sole task of increasing the water pressure in your home. It can be paired with a surface pump or submersible pump or it can be installed between existing pipes in your domestic water system close to the water meter. When paired with a self priming pump, a booster pump can be used to draw water from another source (such as a rainwater tank or river) for better performance.

Booster pumps without tanks

Some booster pumps do not feature a pressure vessel. In this case, the pump has to turn on every time water is drawn in the home which means it uses more energy. If you don't use a lot of water and demand on the system is low, you may not need a pressure vessel. However, if the system is used often, a pressure tank will be required.

Booster pump sets

A booster pump set is a system that incorporates a surface pump, pressure tank and a booster pump (incorporated with the surface pump). The advantage of a booster set is that it works independently since the water held in the pressure tank prevents the system from having to fire up constantly. The pump turns off automatically once the tank is full and the water in the tank provides a buffer to reduce the system's reliance on the pump. The bigger the tank, the less hard the pump has to work which also has an effect on the lifespan of the pump. That said, the larger the tank, the noisier it will be.

When it comes to choosing a booster pump or booster pump set, there are three important criteria to consider: pressure, flow rate and discharge height.

Pressure

The pressure rating of a booster pump dictates the maximum pressure of the water at the head of the system. This will usually be indicated as maximum delivery pressure which is measured in bar.

Discharge height

The maximum discharge head refers to the maximum height at which the pump can deliver water. Measured in metres, this height is used to ensure that the water is able to reach its destination. The delivery height, or pumping height, is equal to the pressure at which water is processed which is why these values are usually noted together. This is easy to calculate since 1 bar equates to about 10 metres. For example, a maximum pressure of 3.8 bar is equivalent to a maximum head of 38 metres.

Flow rate

Flow rate refers to the quantity of water in litres or cubic metres (m3) that can be processed by the pump over a certain period of time, indicated in minutes or hours. To work it out, keep in mind that 6 m3/h equates to 100 l/mn. Remember that flow rate is also linked to delivery height: the greater the delivery height, the lower the flow rate where the diameter of the pump hose (mm) is the same. Conversely, the closer your discharge point is to your water outlets (in terms of height), the greater the flow rate. If your pump is used to supply your home with non-potable water, you'll need a minimum flow rate of about 2 m3/h for five people. Add on 0.25 m3/h for every additional person. If you are using the water to feed an irrigation system, you'll need approximately 1 to 2 m3 per 500 m².

How much pressure do I need?

Comfortable water pressure for residential plumbing sits at about 3 to 4 bar. However, this can vary depending on where you live and your proximity to a water tower or tank. Homes located far from stored water can suffer from low pressure and may need a booster pump to make their system more effective.

The quality of the water you want to pump defines what kind of equipment you can use. If you are using a booster pump to pump water from a well or bore hole, be very careful about the quality of the water. If you have a private well, you are responsible for testing the water to ensure it is safe to drink.

Water quality can be split into three main categories:

• potable water;

• greywater;

• blackwater.

Potable water

Pump boosters can be used to increase the pressure of mains water for potable use, i.e. for drinking. Well water may also be potable but be sure to test the water regularly. Potable water booster pumps might also be referred to as cold water booster pumps. Remember that you must never use a rainwater butt to feed a drinking water tap.

Greywater

Greywater is the wastewater that flows from things like sinks, showers, baths, washing machines or dishwashers. This type of water can be recycled in the home after being treated. In this case, you will need to use a special greywater recycling system which contains a booster pump.

Blackwater

Blackwater is wastewater containing biological material. This water comes from bathrooms and toilets and cannot be reused in the home. Booster pumps do not deal with this type of contaminated water since it needs to be drained away from the home.

A few other important characteristics should be considered when you think about choosing a booster pump:

• The body of the pump should be made of stainless steel or, better yet, cast iron.

• Be sure to choose a pressure tank designed for domestic use.

• A 850/1000W booster pump should be able to make up for low pressure in the home.

• Choose a galvanised steel tank to store potable water for greater durability and fit your system with a water filter.

• Inside the tank is a lining – be sure to check that the lining material is suitable for potable water if required.

• Monocellular pumps feature just one impeller and diffuser while multicellular pumps feature a dual impeller for better performance and lower energy consumption.

• A pressure tank will only contain about a third of its overall 'shell' volume as water with the remaining two thirds filled with pressurised air. The inner lining can be replaced.

• A pressure sensor is used to gauge the level of pressure inside the tank.

• A water pressure test gauge can be used to check water pressure. There are two types of pressure gauge: dry and liquid-filled (the latter of which is recommended for applications subject to vibrations).

• A water level alarm is used to prevent damage to the pump if the water level drops too low.

• A self-priming pump offers more comfortable use.

• Always use a pump strainer and install a non return valve.

Booster pump sets are designed so that the surface pump and booster pump match the size of the pressure tank. If you take care to read all specifications regarding pressure, discharge height and flow rate, there's little chance of making the wrong choice! Finally, make sure to protect the shell from moisture to stop it from getting corroded after a few years of use, especially if it is installed in a damp location or by the sea.