Start with the simplest fixes first

Low shower pressure usually comes from one of three places: a clogged showerhead, a closed or partially closed valve, or sediment blocking the line. Before you call a plumber, check these three things in order, because the first two take five minutes and cost nothing.

Begin by unscrewing your showerhead and holding it up to a light. If you see mineral buildup (white, tan, or rust-colored crusty deposits), soak it in a bowl of white vinegar for two to four hours, then scrub the holes with an old toothbrush and rinse it thoroughly. Screw it back on and test the pressure. This solves the problem in roughly half of all low-pressure complaints.

If the showerhead is clean, locate the shut-off valve for your shower—it's usually behind the wall where the pipe enters, accessible through a panel in the bathroom or an adjacent closet. Turn it counterclockwise (lefty-loosey) to open it fully. If it was only partially open, this will restore your pressure when ready. Mark the fully open position with a piece of tape so you know where it should be.

Key Takeaways

  • A clogged showerhead from mineral buildup is the most common cause and can be fixed by soaking it in white vinegar and scrubbing the holes clean.
  • Check your shower's shut-off valve to make sure it is fully open; a partially closed valve cuts pressure without any other sign of trouble.
  • If pressure is low everywhere in your home, the problem is in your main water line or meter, and you need to call your water company or a licensed plumber.
  • Sediment in the line requires either flushing the system or replacing the affected pipe section, both jobs for a professional plumber.
  • Low pressure in only one or two fixtures usually points to a single valve or line, while low pressure throughout the house points to a larger issue.

Check whether the problem is only in your shower

Before you spend time on your showerhead, turn on the bathroom sink, the kitchen sink, and the toilet tank fill valve. If all of them have normal pressure, the problem is isolated to your shower line. If pressure is low everywhere, skip ahead to the section on whole-house pressure problems.

If only the shower is weak but the sink next to it has good pressure, the issue is in the shower line itself—either the valve, the pipe, or the showerhead. If the sink also has low pressure but the toilet fills normally, the problem may be in the hot water line specifically (since showers usually run hot water). Turn on the cold-water-only tap on your shower if you have one; if cold pressure is normal but hot is weak, your water heater or the hot line has the problem.

What to do if the valve is stuck or damaged

If you turned the shut-off valve and it did not move, or if it moved but pressure did not improve, the valve itself may be stuck or broken. Do not force it—forcing a stuck valve can break it completely and leave you unable to shut off water to your shower in an emergency.

A stuck valve usually means mineral buildup inside it. You can try closing it fully, waiting 30 seconds, then opening it again to see if movement helps break up the deposits. If that does not work, or if the valve moves freely but pressure is still low, the valve needs replacement. This is a job for a licensed plumber, because it requires cutting into the wall and soldering or crimping a new valve into place.

Sediment in the line: when flushing helps and when it does not

If your showerhead is clean, the valve is fully open, and pressure is still low, sediment or rust inside the pipe may be blocking water flow. This is more common in older homes or after work on the water main in your street.

You can try flushing the line by turning the shut-off valve fully closed, waiting two minutes, then opening it fully again. Sometimes this dislodges loose sediment. If pressure improves slightly but not fully, sediment is probably the cause but flushing did not clear it all. At this point, a plumber can either flush the line with higher pressure or, if the sediment is heavy, replace the affected section of pipe. The choice depends on how old the pipe is and whether sediment is likely to return.

Low pressure throughout your whole house

If multiple fixtures have low pressure, the problem is not in your shower—it is in your main water line, your meter, or your water company's supply. Start by checking whether your neighbors have normal pressure. If they do, the problem is on your side of the meter.

Look for your main shut-off valve (usually near the meter, in a basement, crawlspace, or outside) and make sure it is fully open. If it is, and pressure is still low everywhere, call a licensed plumber. They can test the pressure at the meter to see whether the problem is in your home's plumbing or in the supply line from the street. If the problem is in the supply line, your water company needs to know and will usually fix it at no cost to you.

If your neighbors also have low pressure, call your water company directly. They may be doing maintenance, or there may be a break in the main line. The water company can tell you whether service is expected to return to normal and when.

When to call a plumber instead of fixing it yourself

Call a plumber if the shut-off valve will not turn, if you cannot access it, or if turning it did not restore pressure. Also call if pressure is low everywhere in your home, or if low pressure started suddenly after you had no problems before. A sudden change often means a break or blockage in the main line, which requires professional diagnosis.

If you rent, contact your landlord or building maintenance before doing anything. They are responsible for fixing plumbing problems, and opening valves or taking apart fixtures may violate your lease or void a warranty.

Preventing mineral buildup in the future

If your area has hard water (water with high mineral content), your showerhead will clog again. You can slow this down by cleaning the showerhead every three to six months instead of waiting for pressure to drop. Unscrew it, soak it briefly in vinegar, and scrub the holes—this takes about 15 minutes and keeps pressure steady.

Some people install a whole-house water softener to reduce mineral buildup throughout the home, but this is a larger investment. For the shower alone, a replaceable-cartridge showerhead designed for hard water can reduce clogging, though these cost more than a standard showerhead.

Frequently Asked Questions

Can low water pressure damage my water heater?

Low pressure itself does not damage a water heater, but if the problem is in the hot water line specifically, it may indicate a blockage or mineral buildup inside the heater tank. A plumber can flush the tank to restore pressure and prevent future problems.

Why is my shower pressure low but my toilet fills normally?

Toilets use a different valve and line than showers, so low shower pressure with normal toilet fill usually means the problem is in the shower line, valve, or showerhead. The toilet's simpler design makes it less likely to clog or have pressure issues.

Should I replace my showerhead if cleaning it does not work?

If vinegar soaking and scrubbing do not restore pressure, the showerhead is either severely clogged or damaged internally. A new showerhead costs $15 to $50 and is worth trying before calling a plumber, since it is a straightforward swap.

What does it mean if pressure drops only when I use hot water?

This usually means the problem is in the hot water line or inside your water heater. Sediment or mineral buildup in the heater tank is common. A plumber can flush the tank, or you may need to replace it if it is very old.

Can I fix low water pressure by adjusting something under the sink?

Not for shower pressure. The shut-off valve for your shower is usually behind the wall or in a closet, not under the sink. Under-sink valves control only that sink's supply, not the shower.