Low-Flow Shower Heads: Benefits and Flow Rates

A low-flow shower head uses less water per minute than a standard one while trying to keep the spray feeling comfortable. This article explains the flow rates people refer to, the benefits, the caveats, and how to pick one without ending up with a weak shower.

What counts as low-flow?

Flow is measured in gallons per minute (gpm). In the United States, federal rules set a maximum of 2.5 gpm for new showerheads, tested at a standard pressure. The EPA’s WaterSense label applies to showerheads that use no more than 2.0 gpm and meet performance criteria. Many retailers describe anything at or below 2.0 gpm as low-flow, and you will see models rated 1.8, 1.5, or lower. Older showerheads installed before the standards may use considerably more.

Rules vary by country and by state, so check local requirements.

Benefits

• Lower water use. At a lower gpm, each minute uses less water. Savings depend on how long and how often your household showers.
• Lower water heating costs. Less hot water used means less energy to heat it. Because water heating is a significant household energy cost, this is often the larger financial benefit, though the exact amount varies with your fuel type, rates, and habits.
• Quick, inexpensive upgrade. Many models cost a modest amount and install with hand tools, so any payback usually comes within a reasonable time. Claims of specific yearly savings vary across sources, so treat them as estimates and compare with your own bills.
• Lower strain on septic or hot water capacity. A smaller flow can help a small water heater last longer through a family’s showers.

Does low-flow mean low pressure?

Not necessarily. Flow (how much water) and pressure (how hard it pushes) are different things. A well-designed low-flow head uses smaller openings, aeration (mixing air into the stream), or pulsing and jet designs to make the spray feel fuller. Early low-flow designs earned a poor reputation, and quality has improved, but experiences differ between models and between homes. Spray patterns and nozzle designs matter more than the number alone, and it can take trying more than one to find one you like.

Also keep in mind that weak spray can be caused by something else, such as scale in the head or a supply issue. See our guide to common shower problems.

How to tell what flow rate you have

Check the head first. The flow rate is often stamped on the back or edge, or on the box. If it is not visible, use a bucket test:

1. Hold a bucket of known size, such as a one-gallon container, under the shower.
2. Turn the shower on fully to your usual setting.
3. Time how long it takes to fill.
4. Divide the volume by the time in minutes. A gallon filled in 30 seconds is 2 gpm. A gallon filled in 24 seconds is about 2.5 gpm.

If it fills in much less than 24 seconds, your head probably flows above the current standard.

Which flow rate is better?

There is no single best number. Lower flow saves more, but some people find rates much below 1.5 gpm less satisfying, especially in homes with low water pressure (see how to fix low water pressure). Common choices are 2.0 gpm for a balance and 1.5 gpm for stronger savings. If you have a large body-spray system or rain head, flow may be set by the manufacturer or building rules, so check before swapping anything.

Choosing a low-flow shower head

• Look for the WaterSense label if you want independent testing for flow and performance.
• Think about spray style. Fixed heads, handheld wands, rain-style heads, and combination models offer different feels.
• Look at adjustability. Some let you change the pattern, which helps with rinsing or hair washing.
• Consider finish and material. Rubber nozzles are easier to wipe clean of scale. Good finishes resist corrosion.
• Check compatibility. Most connect to a standard shower arm thread, but check the product details.
• Read reviews from people with similar water pressure to yours.

Installing one

Most shower heads can be replaced without a plumber.

1. Unscrew the old head from the shower arm, turning counterclockwise. Wrap a cloth around the fitting to protect the finish if you use a wrench.
2. Clean the threads and remove old plumber’s tape.
3. Wrap new plumber’s tape clockwise around the threads a few times.
4. Hand-tighten the new head, then give it a gentle additional turn if needed. Overtightening can damage the arm or the head.
5. Run the water and check for leaks.

If the shower arm is loose in the wall or you see water around the wall plate, stop and see a plumber, since forcing it can damage the pipe behind the wall. For how the whole system fits together, see how shower plumbing works.

Avoid removing a built-in flow restrictor to get more flow. This may violate rules or the product’s design, and it increases water and energy use.

Downsides and limits

• Savings depend on usage and are not guaranteed.
• Some people dislike the feel of very low flow.
• In homes with hard water, nozzles clog with scale and need periodic cleaning (see is your shower water hard water).
• Where hot water is slow to arrive, a lower flow can make the wait longer, because it takes longer for warm water to reach the shower.
• Low flow in a thermostatic or pressure-balancing system may be affected by the valve minimum flow requirements. If your shower valve acts oddly after a swap, see shower valve problems.