USA Expert Plumbing

Shower valve won't shut off: what to do

By USA Expert Plumbing Editorial Team. Updated . 1 min read.

Short answer

If a shower will not turn off, close the main water shutoff, or the shower's own stop valves if it has them behind an access panel or in the valve body. The usual cause is a worn or broken valve cartridge or stem, often from mineral buildup. Replacing the cartridge is the typical fix, and matching the exact brand and model matters.

In this guide
  1. Stop the water
  2. Why it happens
  3. The fix
  4. When to call a plumber
  5. Types of shower valves
  6. Prevent it

A shower that keeps running after you turn the handle is wasting water every minute. Stop it first, then deal with the cause.

Stop the water

  1. Look for an access panel behind the shower wall, often in a closet or the next room. Some valves have stop valves there.
  2. Some valve bodies have built-in stops under the trim plate, turned with a screwdriver.
  3. If you find neither, close the main water shutoff for the house.

Why it happens

  • A worn or broken cartridge. Single-handle showers use a cartridge that wears or cracks with age.
  • Mineral buildup that jams the cartridge or stem.
  • A stripped handle or stem, so turning the handle no longer moves the valve.
  • Worn washers or seats on older two- and three-handle valves.

The fix

Most repairs mean removing the handle and trim, pulling the old cartridge and installing an exact replacement. Brands such as Moen, Delta and others use different cartridges, and even models within a brand differ. Taking the old cartridge to the store helps.

Before removing a cartridge, note the orientation of the old one. Installing it rotated can swap hot and cold.

When to call a plumber

  • You cannot shut off the water except at the main
  • The cartridge is seized or the valve body is damaged
  • You want to upgrade to a pressure-balance or thermostatic valve

If the valve body itself must be replaced, the job involves opening the wall.

Types of shower valves

Valve typeCommon fix
Single-handle cartridgeReplace the cartridge
Two or three handlesReplace stem washers, seats or stems
Pressure-balanceReplace the cartridge, which includes the balancing spool
ThermostaticClean or replace the thermostatic cartridge

Prevent it

  • In hard water areas, mineral buildup is the main reason cartridges stick. A water softener or regular cleaning of fixtures helps.
  • Do not force a stiff handle; that often breaks the cartridge stem.
  • If a handle starts to feel different, replace the cartridge before it fails.

Common questions

Can I leave the main water off overnight?

Yes, but you will have no water anywhere in the house. Fill a few containers first, and remember to turn off the water heater's heat source if the outage is long.

Is it the cartridge or the valve?

Most running showers are fixed with a new cartridge. The valve body only needs replacing if it is cracked or badly worn.

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