How to Repair a Squealing Shower

In this video, Ask This Old House plumbing and heating expert Richard Trethewey helps a homeowner silence a shrieking shower.

Steps:

1. Turn off the water to the shower at the water main or well pump.

2. Pry off the index from the shower handle with a pocketknife or narrow-blade screwdriver.

3. Unscrew and remove the handle from the shower valve.

4. Use pliers to loosen the retaining nut that secures the mixing-valve cartridge.

5. Pull the cartridge straight out of the valve.

6. Remove the old rubber seats and metal springs from the valve.

7. Install new rubber seats and springs using a Phillips-head screwdriver to guide them into the openings in the valve.

8. Press a new mixing-valve cartridge into the valve, then thread on the retaining nut and tighten with pliers.

9. Push the old handle onto the new cartridge.

10. Turn on the water and test the shower.

11. Remove the handle and use a hex-key wrench to adjust the safety limit on the valve to prevent scalding.

12. If the squealing sound returns, clean or replace the showerhead or tub spout with diverter.

Pro Tip: When installing new seats and springs, use a pencil to guide them into position rather than your fingers. As demonstrated on a This Old House project, this prevents you from dropping small parts into the wall cavity and avoids scoring the backside of the valve body — both of which can turn a simple repair into a much bigger job.

Before inserting the new cartridge, apply a thin coat of waterproof plumber’s grease to the O-rings. Look for the “H” and “C” markings on the cartridge and orient them to match the hot and cold supply sides of the valve. Proper orientation ensures the handle turns in the correct direction for hot and cold water.