5 Reasons for Low Water Pressure in Your Home

low water pressure home

Failing Water Pressure

“Getting in hot water” is an old saying about getting in trouble; those of us in the plumbing trade can tell you that not getting in hot water is an indication of low water pressure. If you’ve ever been in the middle of taking a hot shower that all of a sudden turns cold, you’ve got low water pressure. Of course, other indications of low water pressure are, obviously, water that isn’t coming out of your faucets as fast as normally expected.

To make sure you continue getting in hot water and enjoying normal water pressure, let’s take a look at five reasons for low water pressure in your plumbing system and what you can do to fix it.

  • Hot water heater problems
  • Clogged aerator screen
  • PRV (Pressure Reducing Valve) Issues
  • Water shutoff valve
  • Leaks 

1. Hot Water Heater Problems

If the low water pressure is everywhere, the problem could be your water heater. Here’s how to diagnose whether the water heater is the actual source of the low water pressure problem.

Turn the water on at all your faucets one at a time around the house to determine if the kitchen, bathroom, garage, basement and outdoor faucets all have the same low water pressure. (Note that some faucets may have their own pressure reducing mechanisms in place, such as a low-flow shower head, so exclude them from this test.) 

Run the hot and cold water separately. If both cold and hot water share the same low pressure, the problem is probably not the hot water heater; consider other possible causes below. If you have low pressure only with the hot water, then the hot water heater is likely the source of the problem.

In the case of low pressure for hot water only, inspect the water heater and check the hot water shut off valve. If the valve somehow turned off, turn it back on. If it stays on and hot water pressure resumes to normal, the problem is solved. 

However, if you see any leaks or the shut off valve doesn’t stay on, call a licensed plumber. Hot water heaters can generate a lot of pressure and are dangerous if not handled properly by a knowledgeable professional.

If the problem isn’t a leaky or failing water heater, consider other possible causes for low water pressure.

 2. Clogged Aerator Screen

Is low water pressure coming from both hot and cold lines but only from one faucet? The cause is very often a clogged aerator screen at the end of the faucet. 

This is a simple fix. Unscrew the aerator screen and run the faucet without it. Does the water flow return to normal? If this is the case, the aerator screen is your problem. 

Soak the aerator screen in a water and vinegar solution to remove minerals and other particles that adhered to the screen and prevented water from flowing properly. Once cleaned, replace the aerator screen back in the faucet. If the screen doesn’t come clean or appears damaged, a replacement aerator screen is an inexpensive solution.

3. PRV (Pressure Reducing Valve) Issues

If low pressure is everywhere at every faucet, both hot and cold, check the pressure reducing valve (PRV). Your PRV is most likely found right outside your house where the main water line comes in. It is bell shaped with an adjusting screw on the top. 

Turn the adjusting screw on the PRV clockwise to increase pressure (turning it the opposite way decreases pressure). Go back and run water at all your faucets. Does adjusting the screw correct the low pressure situation? 

If the valve isn’t working or is obviously broken, you need to replace it. Removing and replacing a PRV is not as easy as it might sound; it can potentially cause some complications. This is a job for an experienced Benjamin Franklin plumber

4. Water Shutoff Valve

There is another valve in addition to the PRV to check also. It is the water shutoff valve which, as you might imagine, is used to turn off water to the entire house. If you ever have a burst pipe in the house, turn the water shutoff valve off immediately to prevent any further water damage to your house. 

The house water shut off valve can easily affect water pressure if it is accidentally nudged towards the off position, thus restricting water flow and causing low pressure.

The water shutoff valve is located outside the house at the water meter or near the PRV. Turn the water shut off valve counterclockwise to ensure it is completely open. Check all faucets in the house to see if normal water pressure is restored. 

5. Leaks

If the pressure is low at more than one faucet and none of the above resolved the issue, check for leaks.

Investigate every area where there are plumbing fixtures and check carefully for leaks around the appliances, behind counters, around toilet tank seals, shower heads and faucets and under the kitchen sink where both the water lines are and the connections to the dishwasher run into it. Check the dryness of the cabinet bottom and look for water staining.

Are any of the toilets constantly gurgling or do not fill properly when flushed? Inspect each toilet water tank to determine if the water level is lower than normal or if water is continually running.

How do you know if the water level is too low? A sure sign is if the water is lower than waterline stain on the tank walls. 

If you don’t see a waterline stain and/or hear a constant noise from the toilet, add some food coloring to the tank and wait for an hour or so. If the color now appears in the toilet bowl, there is a leak in the apparatus that controls water in the tank. The first place to look is the flapper, the round rubber that lifts off when the toilet flushes. If it isn’t sealing properly, detach from the chain link and replace. 

Another possibility is the flow valve that regulates water flow into the tank. If it looks old or there is constant water flowing, replace it as well. Both are available from any hardware store or plumbing store. 

Check the water service meter. The service meter measures your water usage. It is located close to the water line into your house or on the side near the electrical meter. Check the leak indicator. If the leak indicator  is turning or spinning, you no doubt have a leak somewhere. 

However, the leak indicator is not sensitive to slow leaks. To check for slow leaks, record the displayed number on the meter of your water usage. Don’t use any water in the house for a few hours. Take another reading after the few hours of no water usage passed. If the numbers are different, there is most likely a slow leak somewhere.

You can call your water company to help determine the source of the leak, but they generally are only concerned with the functionality of their equipment and the water line up to your home. A better solution is to call us at Benjamin Franklin Plumbing. We cover the entire San Francisco and Bay Area. We can not only determine that there is indeed a leak, but we can find it and fix it, most often in one visit.

Low Water Pressure Solved with High Service 

Benjamin Franklin Plumbers handles your low water pressure problems with professional and efficient know-how. Our technicians analyze your water fixtures and plumbing lines and advise you on how to best upgrade your fixtures and their lines to a cleaner, more resource-efficient and aesthetic system to best meet your home and lifestyle goals. An upgrade makes a significant difference to the comfort and class you feel in your own home. 

Benjamin Franklin Plumbers is more than just a plumbing service. We fix. We repair. We replace. But we also design kitchen and bathroom layouts and fixtures with the latest technology in accordance with each homeowner’s goals.

Contact us to help see how we can best assist you.