Low Water Pressure: Common Causes, Fixes, and Potential Concerns
Low water pressure can be a great inconvenience, especially if the problem is worsening over time. Sometimes, low water pressure is an easy fix, while other times, it can be an ongoing problem. Therefore, it's helpful for homeowners to know the common causes of low water pressure, and what they can do to fix this problem. Additionally, homeowners may benefit from knowing the ways to prevent low water pressure from happening in the future.
There are many things that homeowners can do to keep their home's plumbing in good condition. Following best practices can help them maintain their home's value and a good quality of life in their home.
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Is Low Water Pressure a Cause for Concern?
Low water pressure can be the result of a problem as simple as a partially open water main valve that needs to be opened all the way. Additionally, low water pressure can also be the result of a much bigger problem, like a major leak, or the narrowing of the galvanized piping.
Some low water pressure problems can be expensive to fix, while others are inexpensive to address. Either way, it's important for homeowners to thoroughly investigate the problem. For someone who intends to sell their house, low water pressure can reduce a property's value. Low water pressure can cause great inconvenience for households with many people, limiting what can be done with the home's plumbing. Whether it's an easy fix or a potentially major repair that needs to happen, low water pressure can cause a variety of household problems.
Initial Inspections
After discovering there is a problem with their water pressure, the first thing that homeowners should do is try to investigate the potential cause. Low water pressure can happen because of problems with the water supply to the house, so the cause may not be in the actual home itself.
Homeowners should start first at one faucet in the house, like the kitchen or bathroom sink. They should turn on cold water first and then hot water, before turning on both, while noting when water pressure is low and when it is not. Next, they should try the water pressure in another faucet by repeating this process.
If the water pressure is poor in one fixture only, this is a sign of a problem with the water supply to that one plumbing fixture, either at the faucet or in the supply line. If the water pressure is poor in multiple fixtures, this is a sign of a broader problem with the water supply. If the hot water has low pressure, but the cold water is unaffected, this is an indication that there is a problem with the hot water supply from the hot water heater.
Homeowners can uncover these problems by trying all fixtures in their house and by uncovering what works and what doesn't. One thing that homeowners should remember is water supply problems can happen on a macro level. If their entire house is experiencing low water pressure, homeowners should talk to their neighbors to find out if they're also having the same issue.
Water Supplier Issue
If multiple people in the homeowner's neighborhood are experiencing problems with their water pressure, this is likely a sign of a problem with the water supplier. In this situation, homeowners should contact their water supplier to find out if the supplier is aware of a problem impacting the homeowner's neighborhood. In some cases, water regulations can affect the water supply coming to the house. If this is the case for the homeowner, then they may need to buy and have a water pressure booster professionally installed. If the problem is only temporary because of damage that has impacted the entire neighborhood, then the homeowner should wait until the problem is resolved. Homeowners should work with their water supplier to determine the timeline for repair, then follow up if the deadline is not met.
Potential Water Supplier Issues
There are many potential water supplier issues that could affect a home's water pressure, such as:
- A leak or problem with the main water supply in the homeowner's neighborhood. This will likely be addressed quickly, because it affects multiple people.
- A leak or problem with the main water supply to the home. The homeowner may need to follow up to get this problem fixed quickly.
- Changes in government regulations. If the way the water is regulated has changed, this could impact the rate at which water is delivered to the home.
- The water shut-off valve to the house could be slightly closed. Every house has two water shut off valves: one that is used by the utility company and one that is used by the homeowner. If the water supply to a house was recently turned off, either for repairs or for another reason, it could be that the homeowner's utility company failed to turn the water back on all the way.
Faulty Fixtures
Sometimes, low water pressure is the fault of the fixture. Older pipes sometimes have flakes of rust and other debris that flow through the pipes and catch on the aerators and other parts of the fixtures. Sometimes, debris is kicked up in the pipes because of repairs being made, while other times, the debris just flows through the pipes naturally. Either way, when this happens, the fixture either needs to be cleaned out or replaced.
To find out whether the problem is with the fixture, homeowners can unscrew the aerator off the end of the faucet, then flip the aerator over and look inside. If the homeowner can see debris in the aerator, they can use a toothpick to pick the debris out.
In some cases, hard water is to blame for the fixture's clog. Mineral buildup inside fixtures can lead a narrowing of the holes where the water exits the fixture. To get rid of the build up, homeowners can soak the fixture in vinegar for about an hour, then run the fixture under hot water.
Pro tip: Homeowners don't have to unscrew a shower head to get rid of hard water buildup inside the fixture. Instead, they can fill a gallon bag with vinegar and tie the bag to the shower head. Then, they can leave the gallon bag in place for an hour before running hot water through the shower head.
Issues with Pipes
Issues with pipes that cause low water pressure can be serious. If a homeowner has determined that the cause of their low water pressure cannot be traced back to their water service provider or the main water valve, then they should contact a reputable plumber as soon as possible to find the source of the problem.
Closed Shut-Off Valves
In addition to the main shut-off valve on the side of the utility supplier, there's also a main shut-off valve for the homeowner and local shut-off valves at every fixture. Any of these valves could be partially closed.
If the water supply for the entire home has been impacted, then the homeowner should check the main shut-off valve for the house. If the water supply for a single fixture has been impacted, then the homeowner should check the local shut-off valves.
Local shut-off valves are typically found on the wall behind the plumbing fixture, especially if the fixture is not contained in a cabinet such as a toilet. Fixtures that are found in countertops or vanities, like sinks, usually have a shut-off valve on the wall beneath the fixture, often located in the cabinet.
Showers and bathtubs sometimes have shut-off valves inside the wall behind the fixture. To access the shut-off valve, homeowners may find an access panel on the wall behind the fixture. If the local shut-off valve can't be found through an access panel behind the fixture, then it may be found in the basement or crawl space in the house.
The main shut-off valve can be difficult to find, depending on the construction and layout of the home. If a home has a basement, then the shut-off valve will likely be found within 3 to 5 feet of where the water enters the home.
If the home has a crawl space, then homeowners may be able to find the water meter near the kitchen sink or near the water heater. If the home is slab-on-grade construction, then homeowners can likely find the shut-off valve near the water heater or under the kitchen sink.
Major Leaks
Major leaks can cause low water pressure by diverting water from the plumbing fixture to another part of the house. Typically, it is a gushing leak that causes a reduction in water pressure, as small leaks do not usually have a noticeable effect on the water pressure coming out of faucets. This is a good reason for homeowners to get their leak fixed as soon as possible. To find out whether a leak is the source of low water pressure, homeowners will first need to determine if their home has a leak.
To do this, homeowners must turn off all plumbing fixtures and appliances that use water in their house. Then, they should take a reading on their home's water meter, wait fifteen minutes to half an hour, and read the meter again. If the meter changes dramatically in the time when the homeowner is not consuming water in their home, this could be a sign of a major leak. Homeowners should work with a plumber to discover the source of the leak and to see if this fixes their water pressure.
Sometimes, homeowners can tell where the leak might be located by noting which fixtures have low water pressure. If the fixtures that have low water pressure are only located on one side of the house, or if the fixtures are only in one room, this could be a sign that the leak is nearby. Homeowners should look for bubbling paint or mold and mildew, and also listen for the sounds of running water in the walls. These are all indications of a leak nearby.
Clogs in the Pipes
Older pipes can become rusty inside, especially if the pipes are made of galvanized steel. This corrosion usually takes the form of rust and can build up and cause the inside of the pipes to become narrow. Eventually, if the inside of the pipes become too narrow, the water pressure in the house may become very low. If this happens, the only solution is to repipe the home. This can be very costly, but worthwhile.

Sometimes, it's hard for people to tell if corrosion or rust inside the pipes is the cause of the problem, but one of the signs is if the water is rusty red in the mornings. Rusty red water can be an indication of rust in the pipes, which is a sign that there could be a lot of rust buildup inside a home's plumbing.
Another reason that pipes may clog is because of hard water buildup, which can cause the inside of the pipes to narrow just as much as rust inside the pipes. This is preventable because water softeners eliminate hard water and stop minerals in the water from becoming a problem. If a homeowner's pipes have narrowed because of hard water, then the only thing they can do to fix the problem is to repipe their home.
If a home has hard water, a homeowner will be able to tell by the stains that appear on their home's fixtures and appliances. In this case, homeowners should get a water softener before the hard water does permanent damage to their home's plumbing.
Shared Lines
Splitting a plumbing line too many ways can divert the water in too many directions at once. Especially if the shared lines are used regularly, this can result in low water pressure to multiple plumbing fixtures at once. This could happen as the result of a mistake made in the plumbing of the house, or could also be the result of a DIY plumbing job gone wrong. A shared line that results in poor water pressure may need to be fixed by a certified plumber.
Pressure Regulator Problems

Pressure regulator problems are another potential reason that a home's water pressure may be low. The pressure regulator is a device that is placed on a home's main line near the main water valve to the house. The job of the pressure regulator is to reduce very high water pressure coming into the house in order to prevent the water pressure from damaging the pipes.
When the pressure regulator fails, this problem can manifest itself in different ways. One way is that the home's water pressure may become suddenly very harsh. Another indication that the water pressure regulator is failing is if the water pressure becomes suddenly very low.
One of the ways people can determine that a pressure regulator is the problem is that the water pressure in their home will be very low, and adjusting the pressure regulator will do nothing to help. The best way to get a definite confirmation about the problem is for the homeowner to hire a plumber. Homeowners can try to replace the pressure regulator themselves, but replacing this device is not always the easiest task.
How Do Water Pressure Boosters Work?
Water pressure boosters are made up of two parts: an expansion tank and a pump. The tank has a bladder, and when the pump compresses air in the bladder, the bladder becomes pressurized. This enables the pressure booster to shoot water at a much higher pressure than it would otherwise come out.
Pressure boosters are necessary when the pressure of the house falls below 50 PSI, which is widely considered to be normal water pressure for residential use. It can be hard for homeowners to tell if the water pressure in the house is low enough to justify installation of a pressure booster. Homeowners can find out by hiring a plumber to measure the water pressure coming into their house while the plumber also explores possible reasons that the water pressure would be low.
Pressure boosters can be useful for restoring pressure in residential homes. However, pressure boosters can be damaging to a home's pipes if they're too effective. A pressure booster can also be an unnecessary expense, depending on the true cause of the low pressure.
If a plumber does determine that a pressure booster is necessary to restore good water pressure in a home, then homeowners should work with the plumber who knows what the maximum allowed water pressure is for the area (likely around 75 to 80 PSI). Installing a pressure booster that boosts water higher than the allowed amount could result in damage to a homeowner's pipes over time. Therefore, homeowners should monitor their home's water pressure, and notify a plumber as soon as possible if the water pressure seems to go up. This could be an indication that the pressure booster is no longer functioning properly.
How Much Water Pressure Is Too Much Pressure?
How much pressure is too much pressure depends on a homeowner's local building codes. If the homeowner doesn't have a local plumber who can tell them whether their water pressure is too high, the homeowner will need to look it up at their local building department.
Knowing the signs that a home has high water pressure can help homeowners decide when it's time to get help from a professional.
- Water gushes or sputters from the faucet.
- Water pipes bang when they're being used.
- Water slams into the wall of the pipe when the faucet is shut off (water hammer effect).
- The toilets in the house run.
Too much water pressure can also cause a home's appliances (dishwasher, washing machine, and hot water heater) to run down quickly. If someone has noticed their appliances have an unusually short service life, this could be the result of high water pressure, and they should consult with a plumber.
Low Water Pressure? Act Now

Low water pressure is more than just a nuisance: it can be a sign of something problematic happening in a home's plumbing. Homeowners should not ignore the signs of a problem. If they believe that their home has low water pressure, either because of something happening internally in their house or because of something happening outside their home, it's important for them to discover the real problem.
If the problem is happening inside their home, very likely this is something that needs to be addressed as soon as possible. A plumbing leak, narrowing of the home's pipes, and buildup of minerals could all be serious problems. If the problem is a simple clog in the faucet of the homeowner's plumbing fixture, this is an easy fix and one that's worth making.