How A Water Pressure Regulator Works

To ensure you don’t damage your plumbing system or suffer from excessively high pressure, your water supply will be fitted with a water pressure regulator. This is a valve that acts as a gateway between your domestic water supply and the main water line. It works to bring down the pressure to a safe level (which in the UK is between 40 to 80psi).

A water pressure regulator has a pre-set pressure point that makes a valve open and close. On the side of the valve is a pressure sensor, which is a diaphragm with an adjustable spring that can be set at a particular level. When the pressure reaches this level (for example, 50psi), the diaphragm expands, pushes against the spring, which opens the valve. The water then flows from the mains at the correct pressure and into your domestic system.

Why do you need a water pressure regulator?

That’s the technical bit out of the way, so why do you need a pressure regulator? Well, if you were to take your water directly from the mains without this ‘gateway’ regulator, the water coming into your domestic supply would be at a far higher pressure than your pipes and plumbing could withstand. The result would be burst pipes, fractured joints, and a wet floor.

A burst pipe can cause a huge amount of damage, and unless you catch it quickly it can even cause structural damage to your house. Keeping your water supply at the correct pressure ensures that there’s no sudden pressure surge into your plumbing, resulting in a very damp house and a very big repair bill.

Where is the pressure regulator located?

You’ll usually find the pressure regulator where the mains water supply connects with your domestic network, after the main shut-off valve. That is usually inside the property. If you or a plumber needs to repair or change the regulator then you can shut the water supply off before you disconnect it, to prevent the water from coming into your system at full mains pressure.

water presure regulator

Who fits a regulator?

It’s a job for either a professional plumber, or if you’re very good at DIY then you can do it yourself, but you will need to make sure you’re fitting the right kind of regulator and that your water pressure is correct once your regulator has been installed. Remember that a water pressure regulator has to be fitted to your cold water supply, and not your hot water tank. Further attention is required if you are using water filters for your faucets.

Our recommendation is that you leave this job to the experts, as the financial cost of getting it wrong can be pretty high! This is a standard job for a plumber and shouldn’t take more than an hour or so to complete.

You will need to turn off the water supply for that period, but once it’s back on you will be able to monitor the water pressure coming into your system to make sure it doesn’t climb above the recommended levels.

How do I know that a water pressure regulator isn’t working properly?

The best giveaway that your water pressure is too high is pipe knocking when you turn the tap on or flush the loo. You will need to check that it isn’t due to a pipe simply coming loose from its mountings, but that characteristic knocking and vibration when you turn on a tap is usually a sign that the pressure is too high. Check your regulator gauge to see what pressure the water is at and if necessary, adjust the regulator to reduce the pressure. If the knocking carries on, your regulator may be faulty and need changing.

Who do I call to change a regulator?

Because a regulator is usually part of your domestic plumbing, it’s your responsibility to maintain and repair it or get it fixed by a professional. Your water company does not usually deal with faulty domestic regulators, but we can put you in touch with trusted plumbers who can tackle the job for you. A pressure regulator should cost between £25 and £45, plus labour costs.