Short answer
Start by finding out how wide the problem is. If one faucet or shower is weak, check its aerator or showerhead. If the whole house is weak, make sure the main valve is fully open, ask neighbors, and call your water utility. If only hot water is weak, look at the water heater. A sudden drop with no clear cause can mean a leak, so call a plumber.
The cause of low water pressure in a house is often something small. Work from the cheapest, safest check to the most involved one, and find out early whether the problem is inside your home or on the utility's side of the meter.
This is general information from public utility and EPA pages, not a diagnosis of your plumbing.
Step 1: is it one fixture or the whole house?
Turn on a few other taps and a shower. Where the weakness shows up tells you where to look.
| What you see | Likely area | First check |
|---|---|---|
| One faucet or one shower is weak | That fixture | Aerator or showerhead, then the fixture's own shut-off valve |
| Hot water only is weak | Water heater or hot-side piping | See the hot-water section below |
| Hot and cold are weak everywhere | House valves, pressure regulator, supply, or a leak | Main shut-off valve, then ask neighbors |
Some changes are normal. The City of Phoenix says pressure fluctuates, may dip in the morning when many people use water, and can drop for a while during nearby construction.
Low water pressure in the shower or one faucet
When only one fixture is weak, the cause is usually in that fixture. The City of Elgin, Illinois says that when only a few sinks have low pressure, debris may be blocking flow, and it advises you to remove the aerator from the faucet and inspect it for debris. The City of Phoenix lists debris in aerator screens and mineral buildup in galvanized plumbing among the causes of reduced pressure.
- Check the aerator. The aerator is the small screen at the tip of a faucet. Unscrew it by hand, look for grit or flakes, and rinse it out. Follow the maker's cleaning instructions for your fixture.
- Check the showerhead. Mineral buildup can clog the small openings. Take the showerhead off if you can, and clean it using the maker's instructions. If you cannot remove it without force, stop and ask a plumber.
- Look at the flow rating if the showerhead is new. The EPA says a standard showerhead uses 2.5 gallons per minute and a WaterSense labeled showerhead uses no more than 2.0 gallons per minute. The EPA says the label also requires spray force and pressure compensation tests. If the shower got weaker right after a swap, check the new head's flow rating and instructions first.
- Check the shut-off valve under the sink. If it is not fully open, it can restrict flow.
Hot water only: the water heater
If cold water is strong and hot water is weak, the problem is in the hot side: the water heater itself or the pipes after it.
- Sediment in the tank. The City of Blaine, Minnesota says sediment buildup in the tank can reduce a water heater's efficiency and can clog water lines. It says heaters should be flushed every one to three years, depending on the model and water source.
- A failed dip tube. The dip tube is the part inside the heater that carries cold water to the bottom of the tank. Howard County, Maryland traced homeowner complaints of low pressure and less hot water to a disintegrating dip tube whose plastic particles clogged faucet aerators, and says the usual fix was replacing the heater and cleaning all the aerators. The City of Elgin says the particles are white, gray or light green, granular or eggshell-like, and that a dip tube problem needs to be handled by a plumber.
Flushing a tank involves hot water and either electric power or gas, and Blaine says to turn off the electricity or gas first. If you are not comfortable, hire a licensed plumber. For the full steps, see how to flush a water heater. If the heater is also not heating well, read water heater not heating, and if it is old, how long a water heater lasts. It is also worth asking a plumber to confirm that any valve on the pipes at the heater is fully open.
Whole house: main shut-off and meter valves
When every fixture is weak, check the simplest cause first. The City of Phoenix lists a partially closed house valve among the causes of reduced pressure. The City of Chino Hills, California says that if the flow at the outside hose connection is very weak, you should check the gate valve on the standpipe and make sure it is fully open.
- Find your main shut-off valve (see how to shut off your water) and make sure it is open all the way. Turn it gently, and call a plumber if it will not move.
- The valve at the meter normally belongs to the utility's side of the system. Phoenix says the city is responsible for issues from the street to the meter and the homeowner for everything after the meter. Ask your utility whether customers may operate the meter valve before you touch it.
Pressure regulator problems
Many homes have a pressure regulator, also called a pressure reducing valve, where the water line enters the house. It lowers the street pressure to a safer level for your pipes and appliances. Raleigh, North Carolina says the most common cause of unusually low water pressure is a faulty pressure reducer valve, usually on the customer side of the water meter box, and that a plumber can replace it.
Chino Hills says the regulator is the homeowner's responsibility to maintain, that regulators are normally set between 50 and 70 psi, and that older homes may have none. Phoenix says pressure above 80 psi can damage pipes and appliances. Leave adjusting or replacing it to a licensed plumber.
Hidden leaks and old pipes
A leak can reduce the pressure you feel. Look for wet floors, damp walls or ceilings, a wet patch in the yard, or an unexplained rise in your water bill. Many utilities explain how to read your meter to look for a leak. If you find water, shut the water off and read burst pipe: what to do.
Phoenix also lists mineral buildup in galvanized plumbing and a water softener that needs maintenance. If pressure has dropped slowly in an older home, ask a plumber to look at the pipes.
Utility and municipal supply problems
Ask a neighbor whether they have the same trouble. If they do, call your water utility, since the problem may be on its side of the meter. Elgin, for example, tells customers with low pressure all over the house to call the water department. Ask what pressure is normal on your street.
How to check pressure and what the numbers mean
You can test the supply with a pressure gauge made to screw onto an outdoor hose connection. Follow the instructions that come with it, and read it when no water is running in the house.
Ranges differ by utility. Phoenix calls between 40 and 100 psi acceptable on its system. Chino Hills says regulators are normally set between 50 and 70 psi and points customers to its engineering department for the pressure range at a specific location. Chino Hills says the California Plumbing Code requires a regulator on new residential plumbing when main pressure can exceed 80 psi.
Chino Hills also describes a check with no gauge. Good flow at the outside hose connection suggests the problem is inside the house. Very little flow suggests checking the valve at the standpipe, then the regulator.
How to increase water pressure safely
The right fix depends on the cause. In order: clean aerators and the showerhead, make sure house valves are fully open, look for and fix leaks, ask your utility about the supply, then have a plumber test the pressure and check the regulator.
What not to do
- Do not force a stuck valve, or operate the meter valve unless your utility allows it.
- Do not remove or bypass a regulator to get more pressure. Phoenix says pressure above 80 psi can damage pipes and appliances.
When to call a plumber or the utility
| Situation | Call |
|---|---|
| Neighbors are affected, or you see a water main or construction issue | Your water utility |
| Low pressure everywhere and valves are open | A licensed plumber (regulator, pipes, leak check) |
| Water on the floor or yard, or a jump in your bill | Shut off the water, then a plumber |
To vet a company, see drain cleaning near me: how to find and vet a company. The same checks apply to any plumbing job.
What to look up where you live
- Your water utility: where its responsibility ends, whether it can tell you the normal pressure on your street, and its emergency number.
- State or provincial plumbing or contractor licensing board: to confirm a plumber's licence and check complaints.
- Local building or plumbing department: whether replacing a regulator or pipes needs a permit.
- Your home insurance agent: what is covered if a hidden leak causes damage.
For Canadian readers. Plumbing is regulated by each province or territory, and municipalities run their own water systems. Check your municipality and provincial regulator. Pressure ranges and costs differ, and costs are in Canadian dollars.
For plumbing company owners
People who search for low water pressure often end up calling the first plumber they can reach. If you want to be that company, read the plumbing SEO guide and plumber Google Business Profile, or book a call with LiveLeadsLane. LiveLeadsLane is a marketing practice for contractors, not a directory, and it does not take jobs or refer homeowners.
