Start with the shower head and aerator

The fastest fix for low shower pressure is cleaning or replacing the shower head itself. Over time, mineral deposits from hard water build up inside the head and block the small holes that spray water. You do not need a plumber for this—it takes ten minutes and costs nothing if you already have vinegar at home.

Unscrew the shower head by hand (turn counterclockwise). Soak it in a bowl of white vinegar for 30 minutes to an hour. Use an old toothbrush to scrub away the white or tan crusty deposits around the holes. Rinse it under hot water and screw it back on. If pressure returns, you are done. If not, move to the next step.

If soaking does not work, the aerator—a small screen inside the head that mixes air with water—may be clogged or damaged. Unscrew the head again and look for a removable aerator (usually a small cylindrical piece that twists out). Clean it the same way with vinegar and a brush. If it is cracked or the holes are too small, buy a replacement aerator at any hardware store for $3 to $8 and screw it in.

Key Takeaways

  • Mineral buildup in the shower head is the most common cause of low pressure and can usually be fixed by soaking the head in vinegar for 30 minutes.
  • The shut-off valve under the sink or behind the wall may be partially closed and can be opened by hand to restore pressure to the whole bathroom.
  • A clogged mixing valve cartridge inside the faucet body requires replacing the cartridge itself, which costs $15 to $40 and takes 20 minutes with basic tools.
  • If pressure is low throughout your home, the issue is in the main water line or meter, and you should contact your water utility to check for leaks.

Check the shut-off valve under the sink

Every sink has a shut-off valve underneath it—a small knob or lever on the water line. If someone turned this valve partially closed, it will cut pressure to that fixture only. Look under your sink and locate the valve on the hot water line (usually on the left). Turn it all the way counterclockwise until it stops. Do the same for the cold water line on the right.

If the valve is already fully open and you still have low pressure, the valve itself may be stuck or damaged. You can try turning it off completely, waiting 10 seconds, and turning it back on—sometimes this clears a partial blockage. If pressure does not improve, the valve may need replacement, which a plumber can do in 15 minutes for $75 to $150 in labor.

Clean the mixing valve cartridge

Inside your shower faucet is a mixing valve cartridge—a small cylindrical part that blends hot and cold water. If it becomes clogged with mineral deposits, it restricts flow. Replacing it is a job you can do yourself if you are comfortable with basic plumbing, though calling a plumber is also reasonable.

First, turn off the water at the shut-off valves under the sink. Remove the handle by unscrewing the set screw (usually hidden under a decorative cap). Pull off the handle and trim ring. You will see a cartridge—a cylinder about 2 inches long. Unscrew it with a cartridge removal tool (available at hardware stores for $10 to $20) and pull it straight out. Soak the cartridge in vinegar for an hour to dissolve mineral buildup, then reinstall it. If soaking does not restore pressure, buy a replacement cartridge for your faucet brand ($15 to $40) and install the new one the same way.

If you are not confident removing the cartridge, a plumber can do this in 30 to 45 minutes for $150 to $250 in labor and parts.

Check for leaks in your water line

If pressure is low throughout your entire home—not just the shower—the problem is upstream of your fixtures. A leak in the main water line between the meter and your house will reduce pressure everywhere. Look for wet spots in your yard, unusually green patches of grass, or soft ground. Listen near the meter for a hissing sound.

If you suspect a leak, contact your water utility. They can check the meter to see if water is flowing even when all fixtures are off. If water is flowing, you have a leak. The utility will usually locate it for free. Repairing a main line leak requires digging and is a job for a licensed plumber, typically costing $500 to $2,000 depending on the depth and location of the break.

Verify the water pressure from your utility

Municipal water systems deliver pressure between 40 and 80 pounds per square inch (PSI). If your pressure is below 40 PSI, the issue may be on your utility's side, not in your home. You can measure pressure with an inexpensive gauge (available at hardware stores for $8 to $15) that screws onto any outdoor faucet.

Screw the gauge onto an outdoor spigot and turn the water on. Read the number on the dial. If it reads below 40 PSI, call your water utility and report low pressure. They will send someone to check the main line and meter. If the reading is above 40 PSI, the problem is definitely inside your home, and you should focus on the steps above.

When to call a plumber

Call a plumber if cleaning the shower head and checking the shut-off valve do not restore pressure. You should also call if pressure is low throughout your home and you have ruled out a leak, or if you are not comfortable opening the faucet body to replace the cartridge.

A plumber can diagnose the exact cause in 30 minutes to an hour and usually fix it the same day. Costs range from $100 to $300 for a service call plus parts, depending on what needs to be replaced. If the problem is in the main line, expect to pay more for excavation and repair.

Frequently Asked Questions

Can low water pressure damage my plumbing?

Low pressure itself does not damage pipes, but it can indicate a problem that does—like a leak or a failing valve. If pressure drops suddenly, have it checked. Slow leaks can rot wood framing and drywall over months or years.

Will a new shower head with higher flow rate fix low pressure?

No. A new head cannot create pressure that is not there. If your pressure is genuinely low, a new head will not help. However, if your current head is clogged, replacing it (rather than cleaning it) is a quick option. Most shower heads sold today are limited to 2.5 gallons per minute by federal law anyway.

Is low pressure in just one shower different from low pressure everywhere?

Yes. Low pressure in one fixture usually means the problem is in that fixture—the head, the cartridge, or the shut-off valve. Low pressure everywhere points to a main line issue, a leak, or a problem at the meter. Start by checking that one fixture's shut-off valve first.

Can I increase pressure by adjusting something on the water heater?

No. The water heater does not control pressure—it only heats water that is already at the pressure your utility provides. If you have low pressure on both hot and cold, the heater is not the cause.