You stand under the shower and the pressure feels weak. Is there a way to fix low shower water pressure? Corroded water pipes may be the ultimate culprit. But there might be any number of other causes that are easier to address than ripping out all of the pipes in your house. To get started, first determine if you really do have low shower flow by conducting a simple test to measure the flow in gallons per minute (gpm).
Increasing your shower head's flow rate may improve your showering experience and may even lead to shorter showers. But keep in mind that the higher the flow rate, the sooner you will run out of hot water, especially if you have a conventional tank-style water heater (not an on-demand heater).
Equipment / Tools
- 5-gallon bucket
- Stopwatch or timer
- White vinegar
- New shower head (as needed)
Test Your Shower Head's Flow
Turn on the shower to full capacity. Let it run for about a minute. Place a 5-gallon bucket under the water flow, and time how long it takes to fill the bucket. Start the clock as soon as water hits the bottom of the bucket and stop the clock the instant water begins to overflow the bucket.
To calculate the gpm, start with 5 and divide by the amount of time it took to fill the bucket. For example, if the time is 2.5 minutes: 5 divided by 2.5 = 2. The flow is 2 gpm.
For reference, here are the standard benchmarks for gpm flow:
- 1.5 gpm: The standard flow rate from a low-flow shower head
- 2 gpm: The current U.S. Federal WaterSense standard
- 2.5 gpm: The U.S. legal maximum flow for all shower heads, established in 1992
Replace Your Water-Restricting Shower Head
Your shower flow will be minimized if you have a low-flow shower head or you have a shower filter or water-restricting device installed in a regular shower head. Depending on your current flow rate, you may be able to increase the flow simply by removing the filter or restricting device or replacing the shower head with a higher-flow model, such as increasing to a standard 2.5 gpm head.
Before you change the shower head, make sure that the new model is legal in your area. In California, for instance, shower head flows have been narrowing for decades, due to that state's on-going drought problems. Shower heads first went from 2.5 gpm to 2.0 gpm, and then to 1.5 gpm.
Remove Scale Buildup
Over time, mineral deposits and scale clog up your shower head. This is not a matter of "if" but "when," since all tap water contains minerals.
To remove scale from your shower head, unscrew it and submerge it in a bowl of white vinegar for at least eight hours. Then, clean out any remaining particles from individual spray openings with a toothpick. Reinstall the shower head and run the water full-blast to check the flow.
If the deposits will not remove easily, it's time to buy a new shower head.
Check the Curb-Side Main Shutoff
In some cases, you may have been living with low water pressure in your entire house because the curb-side main is not fully turned on. It may have been turned off due to major construction on the home and then not fully turned back on.
Where your water main enters your property at curbside is a water meter and shut-off valve. Check to make sure that the valve is turned on all the way. If the valve has a round handle (like a hose bib), it should be rotated all the way counterclockwise. If it has a lever-type handle, the lever should be parallel to the water pipe.
Usually, you are not allowed to tamper with curb-site meters, so call your water provider if you need to deal with the meter itself. They will send out a worker to check on this for you.
Check the Main Shutoff in the House
A more likely way that a previous homeowner or worker has reduced your water pressure is by turning down the water main value after it enters your house.
There may be various reasons for this. If the previous owners were renting out the house, they may have turned down the volume in an attempt to force the residents to use less water. Or, as with the curb-side main, it may have been turned off due to a water leak or construction, but accidentally not turned all the way back on.
Carefully turn the house shutoff counterclockwise (for a round handle) or parallel to the water pipe (for a lever-type handle). This valve may be corroded and rusty; don't force it.
If any part of the valve or the pipe near the valve looks so corroded that it might break, or if the valve is resistant to turning, call a plumber. You risk breaking the valve or snapping the pipe and flooding the house until you or someone else can shut off the curb-side main.
Another item that influences a shower's water pressure is the volume valve system on a single-handle shower faucet. This is a rather pricey and complicated part that, over time, may compromise your water flow. Because these are difficult to repair, replacement is usually the best option.
Open Up In-Line Shut-Off Valves
Some homes have a in-line, or fixture, shutoff valves on the water lines supplying the shower head, similar to those found on sink supply lines. These valves are on individual branch pipelines and they act as emergency stops. They are convenient if you are doing work in a local area (shower, toilet, sink, etc.) and do not wish to shut off the water in the entire home.
These shutoff valves, if you have them, are likely to be located near the supply point. For a shower that has supply pipes in the basement, these shutoffs would be located on the pipes leading up to the shower.
As with the main water shutoffs, it's possible that small fixture valves are not fully open. Turn these valves counterclockwise all the way for full pressure.