Low Water Pressure: Common Causes, Troubleshooting, and When to Call a Plumber

Low water pressure in home may make it difficult to shower, wash dishes, do laundry and clean. This can be caused by minor issues such as a clogged faucet screen or a partially closed valve, but it can also indicate leaks, old pipes, water heater problems, or a problem with the main water supply. In this article, homeowners will learn how to identify low water pressure, some of the common causes, how to test various fixtures, and when to contact a plumber.

Common Causes Of Low Water Pressure

There are many causes for low water pressure. Some causes are minor and can be easily corrected, and others may require the services of a plumber to inspect the plumbing system.

1. Clogged Faucet Aerators

The small screen at the end of the faucet is called a faucet aerator. It will accumulate minerals, dirt and small particles over time. When the aerator becomes clogged, water comes out slowly. This is typically a problem with only one faucet and is often solved by cleaning the screen.

2. Blocked Showerheads

Mineral deposits can also build up in showerheads, particularly in hard water areas. Small spray holes can clog and cause a decreased flow rate. When the showerhead is clogged, the water may not spray evenly or feel as strong as it should. Sometimes, a showerhead cleaning or replacement can help to improve the pressure.

3. Partially Closed Valves

A water valve may be partially closed after repairs, cleaning or maintenance. It may be at the main water valve, under-sink valves, toilet valves and the water heater valve. Even a slightly closed valve can decrease the amount of water that gets to the fixture.

4. Hidden Plumbing Leaks

One of the more serious reasons for low water pressure in kitchen sinks is leaks. Water can leak from a pipe before it gets to the faucet or shower. Signs of a leak may include wet floors, water stains on walls, mold odors, or an unexpected increase in water bills. 

5. Old Or Corroded Pipes

Older pipes may become constricted due to rust, scale or mineral deposits. This will make it more difficult for water to flow through the plumbing. Old galvanized pipes are more susceptible to this issue. When multiple fixtures have low pressure, it may be necessary to inspect the pipes.

6. Faulty Pressure Regulator

Some houses have a pressure regulator that regulates the water pressure coming into the house. When this section fails, the water pressure in the home can suddenly become very low or very high. Typically, a leaking pressure regulator will impact the entire home, rather than just a single faucet.

How To Troubleshoot Low Water Pressure

There are a few things that homeowners can do before they call the plumber. These measures can help determine if the problem is minor, fixture-related or a plumbing problem.

• Test Sinks, Showers, Toilets, Outdoor Faucets, Appliances: Homeowners should check fixtures. If one fixture is weak, it could be a local problem, but if the entire house has low water pressure, it could be a problem with the main plumbing.
• Hot vs. Cold Water Pressure: Test hot and cold water individually. If the hot water pressure is low, it could be either the water heater or the hot water line.
• Clean Faucet Aerators: If one faucet is clogged, its aerator may be clogged, which will cause the water to flow slower. It can be taken off, cleaned of debris, soaked in vinegar, and then put back in place by homeowners.
• Check the Showerhead: Mineral deposits can clog the showerhead spray holes and reduce pressure. If the showerhead is old or damaged, it can be soaked in vinegar or replaced.
• Inspect Shut-Off Valves: Main valve, water meter valve, under-sink valves and water heater valve should be completely open. A partially closed valve can cause a decrease in water flow.
• Watch for Leak Warning Signs: Water stains, a moldy odor, damp walls, unusually high water bills or wet spots in the yard can be signs of a leak. Even when all the fixtures are turned off, a running water meter can be a warning sign as well.
• Use a Water Pressure Gauge: A pressure gauge can indicate if the home is truly experiencing low water pressure. If the reading is normal, then the problem may be a fixture blockage.

When To Call A Professional Plumber

There are some issues with low water pressure that are simple but some require professional repair. Call a plumber if the problem is affecting the entire home, has occurred suddenly or if there are signs of a hidden problem.

Pressure is Low Throughout the Whole Home

If all the faucets, showers, toilets and appliances are experiencing low pressure, it could be a bigger issue than one fixture. It can be caused by the main water line, pressure regulator, pipe corrosion or a leak that is hidden. A plumber will be able to examine the entire system and determine the actual cause.

Water Pressure Drops Suddenly

Don't ignore a sudden drop in water pressure. This can occur due to a leaky pipe, broken valve, municipal water problem or main supply problem. Quick inspections can prevent further plumbing issues.

Signs of Leaks or Water Damage

Water stains, mold odors, puddles, soft floors, wet walls, and unusually high water bills are signs that a plumber should be called. These signs could indicate that there is a leak somewhere in the house or in the ground. Early repair will help prevent damage to floors, walls and the plumbing system.

Only Hot Water Pressure is Low

If hot water pressure is low but cold water pressure is good, the water heater may be the cause. Hot water flow can be impacted by sediment buildup, valve problems, or tank problems. When dealing with water heater work, care needs to be taken as it contains heat, pressure and safety components.

Pipes are Old, Rusty or Corroded

Older pipes may narrow, rust or weaken over time. This can lead to lower water pressure and potentially higher leak risks. A plumber will be able to examine the pipes and let you know whether cleaning, repair, or pipe replacement is necessary.

The Bottom Line

Low water pressure in house can be due to clogged aerators, partly closed valves or it can be a sign of leaks, old pipes or water heater problems. A homeowner can inspect for basic causes, but if the pressure is low throughout the home, drops suddenly or is showing signs of damage, a professional plumber should inspect it.

Disclaimer: This material is for informational purposes only and should not be relied on for legal, medical, financial, or any other form of professional advice.