How a Water Pressure Regulator Works

A man attempting to fix a sink in a kitchen
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A water pressure regulator is a plumbing valve that reduces the water pressure coming from the main water line into the house. This valve brings down the pressure to a safe level before the water reaches any plumbing fixtures inside the home. Too much water pressure will cause many plumbing problems for the average homeowner, so it is very important to keep the water pressure under control.

Where Is It Located?

A water pressure regulator, if you have one, is usually located where the main water line comes into the house and after the main shut off valve. This way if you need to work on or change the water pressure regulator you can simply shut off the water main to do so.

How Does It Work?

An adjustable spring-loaded diaphragm inside a water pressure regulator reduces the pressure of the water in the line within the valve body. Water coming into the valve is constricted and then released at reduced pressure.

Do I Need One?

To determine if you need a water pressure regulator test the water pressure of the main water supply to your house. You can buy a pressure gauge for local hardware or home improvement store. Screw the pressure gauge onto any hose bib or washing machine bib and turn the water on to measure the water pressure. If the pressure is between 40 and 60 psi consistently then you should be fine. Keep watch because there can be some fluctuations at night if you are on city water as the load goes down, so test it at various times. When testing the water pressure, you must make sure water isn’t being used anywhere inside or outside the house.

Another precaution is to ask the local water company; they can often tell you if a pressure regulator may be required in your neighborhood.

Is a Pressure Regulator Easy to Install?

If you already have an existing pressure regulator, it can be very easy to replace it with the same brand and model regulator in the same spot. Most manufacturers do not change the shape or size of their regulators so a new one should fit exactly how the old one did. It can be as easy as shutting off the water removing 1 or 2 unions and unscrewing or pulling the valve out of position and installing the new one the opposite way the old one came out.

A new installation, on the other hand, is more difficult because it will require some adjustment to the main water line. This could mean reworking the main water shutoff valve, so it is lower to allow for room for the regulator. You may want to call some local plumbers to get estimates before deciding to do the project yourself.

How Can I Tell When a Pressure Regulator Goes Bad?

Like all plumbing fixtures and valves, water pressure regulators will go bad at some point. If you notice water hammering of any type, more water pressure, less water pressure, or other inconsistencies in the water pressure it may be an indicator that the water pressure regulator is not working properly. Test the water pressure with a gauge if there is any question of the regulator’s effectiveness. Testing the water pressure at least once a year is always a good idea. Too much water pressure will put extra strain on the home’s plumbing systems and can cause toilets to run, faucets to drip, water hammers to occur in the walls, and in extreme cases, it can a burst pipe and flood your house.