Low Water Pressure When Using Two Faucets

Do you notice low water pressure or a sudden drop in water pressure when you use two faucets? This is an annoying and common problem in bathrooms, kitchens and other areas with two faucets or water sources.

If you are having water pressure problems with your faucets, use this troubleshooting guide to fix your plumbing problems.

What Can Cause Low Water Pressure?

There are many things that can trigger low water pressure. When water pressure is struggling in one faucet and the problem is isolated to that one faucet, the problem is usually quick and easy to decipher. In cases where the water pressure drops after a few seconds of running several faucets, the culprit could be several different things.

Pressure Reducing Valve

Problems with the pressure-reducing valve can lead to low water pressure. If the water pressure starts out normal and then drops, the pressure-reducing valve may be the cause of the problem. They are usually located in municipal systems or where the water pressure exceeds 80 pounds per square inch.

When water pressure is too high, pipes and equipment may be damaged. If the problem is with the pressure-reducing valve, try adjusting the valve to see if it affects the water pressure in your home. If there is no effect, the entire unit may need to be replaced.

If your water comes from a private well, the water to your home is pressurized through a pressure tank that maintains a specific pressure range. In a residence, the ideal water pressure should be between 45 and 55 pounds per square inch. However, it usually ranges between 45 and 80 pounds per square inch.

Shutoff Valves

Check the shutoff valves, both for the main water system and for both faucets. If the valve is even slightly closed, it could affect your water pressure, so check to make sure it’s fully open. If you’ve recently had work done on the pipes in your home, or if a child may have bumped into the valve, a shutoff valve in the slightly closed position could be the problem.

If your sink has shutoff valves for cold and hot water and you experience low cold water pressure, the shutoff valve dedicated to cold water may be slightly off.

The shut-off valve for a particular faucet may be underneath the sink itself. The main water supply shutoff valve maybe near your furnace or water heater, or within three to five feet of where the water line enters the home.

Trapped Air

When air is trapped in a pipe, it can cause fluctuations in the water pressure in your home. As water flows through the pipes to your faucet, it acts as a sort of valve, causing spills and occasional bursts of water from the faucet.

Air can enter the pipes through damaged tank bladders, failed pumps, leaking suction lines, leaks in the pipes, or a build-up of gas in the well water system.

Clogged Pipes

If the pipes in your house become clogged for any reason, it can lead to a lack of water pressure in your home’s faucets. The water flow becomes turbulent, which reduces the water pressure in specific areas of your home.

This problem requires hands-on work and will likely need to be handled by a professional unless you are a skilled DIYer.

Corroded Plumbing

Over time, the pipes in your home can corrode, causing a full-blown problem. If the corrosion is severe enough, leaks, loss of water pressure and other problems may occur. Replacing all the pipes in your home is a huge undertaking and will be an expensive adventure, but it’s worth the effort.

Plumbing in older homes tends to corrode, as most pipes have a life expectancy of between 20 and 100 years. Galvanized steel pipes typically last between 20 and 50 years, while copper, brass and iron materials may last between 40 and 100 years.

Corroded plumbing may result in the low water pressure inside the home as well as at outdoor faucets. Corroded or leaking pipes may affect garden hose spigots, outdoor faucets, etc.

Broken Water Pipes

Broken or crushed water pipes may also be the culprit. Broken or crushed water pipes usually cause problems throughout the home and are not usually isolated to two faucets.

Can A Bad Faucet Cause Low Water Pressure?

A faulty faucet can lead to low water pressure. Bad parts inside a faucet, such as a clogged aerator or clogged cartridge, can cause a sudden drop in water pressure.

A bad faucet can cause water pressure fluctuations between two faucets in the same room. For troubleshooting situations where water pressure is low between two faucets in the same room, the first step is to check the faucet itself.

 

How Do I Fix It?

If you can determine which of the two faucets seems to have low pressure, start with that one. Turn off the water supply to the faucet before taking it apart. So, remove one end of the faucet and inspect your aerator, the piece that goes inside the spout.

Verify that it is clean and free of any mineral buildup or other debris. If there is debris in the aerator, soak it in a solution of water and vinegar. However, if that solution does not loosen the debris, you may need to purchase a replacement part.

Before replacing the aerator, turn on the water supply and check the flow of water from the faucet. If the faucet still shows low flow, then the low water pressure is likely not due to that particular faucet, but maybe a general problem.

Do Mixing Valves Reduce Water Pressure?

Some types of shower valves have what is called a thermostatic mixing valve, which controls the water temperature and water pressure separately. It is possible that a malfunctioning mixing valve could cause a reduction in water pressure.