Why your outdoor faucet has low pressure and what you can do about it
Low pressure at an outdoor faucet usually comes from one of three places: a clogged aerator, a kinked or blocked supply line, or a shutoff valve that is not fully open. The good news is that you can check and fix all three yourself in under an hour, and none of them require special tools or plumbing knowledge. Start by ruling out the simplest culprit first—the aerator—then work backward toward the main water supply.
If pressure is low everywhere outside but normal inside, the problem is likely in the outdoor line itself or the valve that feeds it. If pressure is low only at one faucet, the problem is almost certainly at that faucet. This distinction tells you where to focus your effort.
Key Takeaways
- The aerator—a small screen at the faucet tip—clogs easily and is the most common cause of low outdoor water pressure; unscrew it and rinse it clean or replace it.
- Check that the shutoff valve for the outdoor line is fully open by turning the handle parallel to the pipe; if it is perpendicular, it is closed.
- Inspect the supply hose or buried line for kinks, cracks, or damage that could restrict flow; a kinked hose can be straightened or replaced for under twenty dollars.
- If pressure is low everywhere outside but normal inside, the problem is in the outdoor supply line or its valve, not at individual faucets.
- If you find no blockage and the valve is fully open, the issue may be a failing pressure regulator or a problem in the main water line, which requires a plumber.
Clean or replace the aerator
The aerator is the small screen or strainer screwed onto the tip of your faucet. It mixes air into the water stream and prevents splashing, but it also traps sediment, mineral deposits, and debris. Over time, especially if your water is hard or your area has old pipes, the aerator clogs and restricts flow.
To clean it, turn off the water and unscrew the aerator by hand or with a wrench if it is stuck. Rinse it under a strong indoor faucet to dislodge debris. If you see white or tan buildup (mineral deposits), soak it in white vinegar for thirty minutes, then scrub it with an old toothbrush and rinse again. Screw it back on and test the pressure. If the aerator is cracked or the screen is damaged, buy a replacement at any hardware store for two to five dollars—they are universal and take thirty seconds to install.
Check the outdoor shutoff valve
Most homes have a shutoff valve where the outdoor water line branches off from the main supply, usually in the basement, crawlspace, or garage. This valve controls water to all outdoor faucets. If it is partially closed, pressure will drop everywhere outside.
Locate the valve and look at the handle. If the handle is parallel to the pipe (pointing the same direction as the water flows), the valve is open. If the handle is perpendicular to the pipe (at a right angle), the valve is closed or partially closed. Turn the handle so it is parallel to the pipe, then test your outdoor faucet. This is one of the most common causes of low outdoor pressure and takes ten seconds to fix.
Inspect the supply hose or line for damage
If your outdoor faucet is fed by a hose that runs above ground, look along its entire length for kinks, cracks, or pinch points. A kinked hose can reduce pressure dramatically even if the kink is not visible at first glance. Straighten any kinks by hand or by running warm water through the hose to soften it. If the hose is cracked or has a hole, replace it—outdoor hoses cost ten to thirty dollars depending on length and quality.
If the line is buried underground, you cannot inspect it visually, but you can test whether it is the problem. Turn on the outdoor faucet and listen for hissing or spraying sounds near the ground along the line's path. Wet spots in the yard or unusually green patches of grass also suggest a leak. If you suspect a buried line is damaged, a plumber can use a camera to inspect it and locate the break.
Test water pressure at the source
To narrow down whether the problem is at the faucet or in the supply line, test pressure at the point where the line enters the house. If you have a frost-proof faucet (the kind that drains automatically in winter), turn it on fully and note the pressure. Then go inside and turn on an indoor faucet on the same side of the house. If indoor pressure is normal but outdoor is low, the problem is in the outdoor line or at the outdoor faucet itself. If both are low, the problem is likely in the main water supply or the pressure regulator.
A pressure gauge, available at any hardware store for ten to twenty dollars, gives you an exact reading. Screw it onto the outdoor faucet (you may need an adapter) and note the number. Normal household water pressure is between 40 and 80 pounds per square inch (PSI). If your gauge reads below 40 PSI, you have a pressure problem; if it reads above 80 PSI, you have high pressure, which is a different issue.
Check for leaks in the outdoor line
A slow leak in an underground or buried outdoor line can reduce pressure without being obvious. Walk the path of the outdoor water line and look for soft spots in the ground, puddles that appear after you water, or patches of grass that stay wet longer than others. In winter, look for ice formations in unusual places.
If you find a wet spot, mark it and turn off the outdoor shutoff valve. If the wet spot dries up, the leak is in the outdoor line. If it stays wet, the leak is in the main supply line, which is a job for a plumber. A small leak in an outdoor line can sometimes be patched temporarily with plumber's tape or epoxy putty, but a permanent fix usually means replacing the damaged section.
When to call a plumber
If you have cleaned the aerator, confirmed the shutoff valve is fully open, inspected the hose for damage, and pressure is still low, the problem is likely in the main water supply line, the pressure regulator, or the internal plumbing of your home. A pressure regulator is a device that controls water pressure from the street; if it fails, pressure drops everywhere or becomes erratic. This is not a repair you can do yourself.
Call a plumber if pressure remains low after you have ruled out the aerator, shutoff valve, and visible hose damage. Bring your pressure gauge reading with you if you have one—it helps the plumber diagnose the problem faster. Most plumbers charge a service call fee of seventy-five to one hundred fifty dollars, plus the cost of any repairs.
Frequently Asked Questions
Can low outdoor water pressure be caused by the city water supply?
Yes. If pressure is low everywhere in your home, including indoor faucets, the problem is likely in the main water line or the city supply. Contact your water utility to report low pressure; they can test the line from the street to your meter. If the problem is on their side, they fix it at no cost.
Why does my outdoor faucet have low pressure but my indoor faucets are fine?
The outdoor line is separate from the indoor plumbing, so a problem in the outdoor line does not affect indoor faucets. Check the outdoor shutoff valve, the aerator, and the supply hose first. If all three are clear, the problem is likely a leak or blockage in the buried outdoor line.
Will a new outdoor faucet fix low pressure?
Only if the faucet itself is damaged or the aerator is beyond cleaning. If pressure is low at the faucet but the aerator is clean and the shutoff valve is open, replacing the faucet will not help. The problem is upstream in the supply line.
How do I know if my pressure regulator is failing?
A failing regulator usually causes pressure to drop everywhere in the home, not just outside. You may also notice pressure that fluctuates or spikes suddenly. A plumber can test the regulator with a gauge; if it is faulty, it costs one hundred to three hundred dollars to replace, depending on the type.
Can I increase water pressure by adjusting something myself?
You can only increase pressure by removing blockages or opening a closed valve. You cannot artificially boost pressure without a pump. If you have removed all blockages and the valve is fully open, pressure is limited by your water supply and cannot be increased without installing a booster pump, which a plumber must do.