How to prevent backflow

1. Make sure your pipes and appliances are protected

Sometimes, the water pressure in the mains supply can become lower than the pressure in your pipes. When this happens, the water could travel in the wrong direction. And if it does, it could end up contaminating the water supply. So if you want to keep your supply safe, make sure that your pipes and appliances are fitted with a backflow prevention device. A non-return valve, for example, is a simple, low-cost solution that only allows water to flow through it in one direction – the right one. That means that if you do have a loss of mains water pressure, the valve won't let any of your potentially contaminated water back into the supply, and you won't suffer from backflow in your plumbing.

2. Check your garden taps

When you use the taps in your kitchen or bathroom, they're usually protected by the vertical gap between the tap and the sink: any water would have to defy gravity to climb back from the drain into the tap. But garden taps are often used with hoses. And without that gap of air to protect it, water could start moving back into the supply. So if you want to keep your plumbing safe, make sure all of your garden taps are fitted with a backflow prevention device, such as a double-check valve.

3. Keep your shower tidy

If you let your shower-head or hose lie in the standing water at the bottom of your bath or shower, you might be letting water flow back into your supply. So when you're finished, keep the shower-head in the proper holder, and don't let it fall into water that might be contaminated.