This page has been written to inform customers of ShowerPowerBooster as to why and where you have check valves in your home. This may help you understand why you might have problems and how to fix them.

The Check Valve in a ShowerPowerBooster

There is a 22mm single check valve within the body of a ShowerPowerBooster. In the event of an electrical failure this valve will fully open so that the water you received through the pipe where the Shower Power Booster is fitted is the same as before you fitted it. Water will bypass this check valve in either direction which is unique way we operate the pump (patented).

If you have need to prevent water flowing back from a mains pressure cold because of a failed check valve in your system you cannot rely on the SPB check valve but you can fit a 22mm single check valve either before or after the ShowerPowerBooster.

Cold mains feed into your home

It is a legal requirement that you have a double check valve on the mains pipe coming into your home. This check valve is to prevent back flow of water if there is a burst water main. To comply with UK Water Regulations this needs to be a double check valve. If you suffer from low pressure mains pressure and you have the normal 15mm double check valve then there will be significant pressure loss so we advise you replace it with a 22mm check valve and use 3 part 22mm to 15mm reducers. The pressure loss through a 22mm check valve is much less than a 15mm check valve.

Mixer Showers and Mixer Taps

There is normally a non return valve which is 15mm or less on the hot side and cold side of a mixer valve and this non return valve is part of the mixer. There is no law which prevents suppliers selling substandard mixers into the UK which do not have non return valves and many of the mixers sold, including a few well know prestigious brands, have no non return valves. Other mixers are so badly designed and have springs that prevent water at low pressure from forcing its way past. If the flow to your tap or shower is not sufficient to activate the SPB flow switch then removing the non return valves could solve it. If you have mains pressure on the cold and gravity hot then you will need a 22mm single check valve before or after the ShowerPowerBooster.

Shower Power Booster – Automatic Negative Head Solution

It is possible to remove non return valves from mixer showers and taps for ShowerPowerBoosters to work automatically in negative head situations – click this link to read more.