Shower water pressure is low

What should you check first when the shower is weak?

Turn on the bathroom sink and a kitchen tap. Strong flow there means the trouble sits in the shower itself: the head, the valve or the pipe that feeds it. Weak flow everywhere points further back, to a regulator, a leak or tired supply pipe, with the shower merely the place you notice it.

That thirty-second comparison saves money. If the whole house is sluggish, read why house water pressure drops and pressure that falls suddenly before touching the shower. If only the shower struggles, carry on down this page. Other bathroom and kitchen fixtures are grouped under faucet, sink and shower repair.

Is a scaled-up showerhead the culprit?

Very often. Mineral crust plugs the little nozzles and the screen behind them, and many heads carry a built-in flow restrictor as well. Unscrew the head and inspect the face. White crust or grit means scale. Let the head soak in a bowl of household vinegar for about sixty minutes, rinse it, and see whether the spray perks up.

Cleaning goes like this:

1. Twist the head off the arm, with a cloth around the nut to spare the finish.
2. Lift out the filter screen and the restrictor disc if the head has them, and rinse both under the tap.
3. Submerge the nozzle face in a bag of vinegar held on with a rubber band, then poke each hole clear with a pin or old toothbrush.
4. Rinse, rewrap the arm threads with fresh PTFE tape and screw the head back on.

Look at the flow rating printed on the head. Title 20 sets California's flow ceiling for showerheads at 1.8 gallons per minute when tested at 80 psi. A newer head can therefore feel gentler than an old 2.5 gpm one, on purpose. Choosing a pattern that concentrates the spray helps a low-flow head feel livelier; showerheads for low pressure compares options.

Does Long Beach water leave scale in the shower?

Water hardness varies by source, and a supplier's yearly water quality report is the place to read the number. Long Beach Utilities publishes one, and San Pedro and Wilmington customers are served by a different utility with its own. Minerals deposit on heads, inside valves and, over time, on pipe walls.

Heat accelerates deposits, so scale tends to be worse on the hot side. A shower that is weaker on hot than on cold, or one that has faded gradually over many months, hints at buildup in the head, the valve or the heater. Descaling methods that are safe for fixtures appear in hard water scale removal, and a treatment system is the long-term answer, outlined in water softener installation.

Might the shower valve or cartridge be wearing out?

Yes. A cartridge choked with debris or simply worn, or a mixing valve in decline, can throttle the shower alone while the other fixtures behave normally. Clues include flow that is weak on one temperature only, a gritty handle, drifting temperature or a drip from the spout.

Once the trim is off, a cartridge swap is about a one or two hour job. A damaged valve body means opening the wall behind the tile. Some shower valves have small built-in stops that get set partway during other plumbing work, so a shower that went weak right after a repair deserves a look there. The cartridge brand and model decide the replacement, and a plumber can identify it. Related pages: a shower leak and a dripping tub faucet.

Can the pressure regulator or old pipe cause a weak shower?

They can. A failing or low-set regulator, a main that is not fully opened, a hidden leak or rust-narrowed galvanized pipe can each take pressure away. The shower sits at the end of the line, so it reports the problem first. A low-cost gauge screwed on an outdoor spigot gives a static reading.

Readings in the range of 40 to 80 psi are generally workable. Plumbing code section 608.2 expects a regulator whenever static pressure on the supply tops 80 psi, one reason many houses carry one near the main. Before blaming the utility, read about adjusting a regulator and replacing one.

In bungalows built before 1960 in Belmont Shore, Bixby Knolls and Naples, original galvanized lines may have a fraction of their original bore left. No fixture swap fixes that, and the answer is a repipe, discussed in repipe house. When only hot is weak, make sure the heater's outlet valve is wide open and see low hot water pressure.

Who fixes a weak shower, and what does it involve?

The local plumber reads static and flowing pressure, inspects head, valve and supply, and says whether you face a quick cleaning, a cartridge, a regulator or a repipe. Anything behind tile or inside the wall is contractor work, and jobs from $1,000 up legally require a California contractor license.

Tell us which showers are weak, whether hot, cold or both, and what you have tried, using the quote form. Requests are handled on weekdays, 9am through 5pm. A visit is arranged and you get a written number before work. For the full process, see the Harbor Lights home page. Whole-house cases belong with plumber for low water pressure.

Common questions

How long will I be without the shower?

Cleaning the head is quick. A cartridge swap fills an hour or two, a new valve longer because tile may come off, and regulator or repipe work depends on the house. Have the plumber write the time on the quote and say when the water goes off.

Which questions help me compare plumbers?

Will pressure be read first? How will the head, valve and supply be ruled in or out? Does the price cover a second visit if the first fix fails? Obtain the contractor license number plus the scope on paper before anyone cuts into tile.

Why is the shower weak only when it is hot?

Usually scale, a heater valve that is partly shut, a clogged cartridge or sediment in the heater. See whether the hot side is weak at other taps too. If it is, look at the heater and its valves. If only the shower is affected, suspect the cartridge or mixing valve.

Can the flow restrictor in a showerhead be removed?

It can, and many people pop out the small disc. The 1.8 gallons a minute ceiling is a state rule, and pulling the disc out raises water and heating use. Descaling the head, or picking a model engineered for a strong feel at low flow, is the better way to a firmer spray.

Does a weak shower mean there is a leak?

Sometimes. A leak in the supply line can drop pressure at every fixture, and the shower, being furthest along, shows it first. Read the meter with everything off. If the meter keeps turning, a leak needs tracking down, and clues that a pipe has burst is a place to begin.