Caleb MorganBy Caleb Morgan

Updated November 2026

To repair a tub faucet diverter, you will shut off the water, remove the handle and trim, pull out the diverter stem or cartridge, clean or replace the worn seal, and reassemble the valve. Most diverter problems come down to a worn rubber washer, a corroded stem or mineral buildup that stops the pop-up from seating. The job usually takes under an hour with basic hand tools.

Identify the Type of Diverter Before You Start

Not every tub diverter works the same way. Some use a pull-up knob on the spout, some use a lever on the faucet body, and others use a separate valve built into the stem. Check which style you have, because it determines what you need to remove. If water keeps coming out of the spout when you switch to the showerhead, or the showerhead stays weak, the diverter is likely not sealing fully. Confirm this by running the tub, switching to the shower and watching for water at the spout.

Shopping for one? See our guide: 6 Best Repair Tub Faucet Diverter Kits Compared (2026).

Shut Off Water and Remove the Handle

Close the main water supply or the shutoff valves under the tub access panel. Open the tub faucet to drain any remaining water. Then follow these steps:

  1. Pry off the decorative cap on the handle with a flat screwdriver or fingernail.
  2. Remove the handle screw and lift the handle off the stem.
  3. Unscrew the escutcheon (trim plate) and the packing nut or retaining nut.
  4. Keep all small parts in a labeled container so you can reassemble in the correct order.

Remove and Inspect the Diverter Assembly

Pull out the diverter stem or cartridge. Many diverters slide out once the retaining nut is off. If it is stuck, wrap a rag around it and use pliers gently. Look for these common problems:

  • Worn rubber washer or O-ring: Flattened, cracked or split rubber will let water leak past the diverter.
  • Mineral scale: White or greenish crust can block the pop-up from moving freely.
  • Corroded metal stem: Pitting prevents a tight seal even after cleaning.

Clean scale with white vinegar and a soft brush. Do not scrub brass or chrome with abrasive pads, as this can strip the finish.

Replace Worn Parts and Reassemble

Replace the washer or O-ring using the exact size from the original part. Take the old washer to a hardware store if you are unsure. Apply a thin layer of plumber’s silicone grease to the new rubber to help it seat and slide. Reinstall the diverter, tighten the retaining nut snugly without overtightening, then refit the handle and trim.

If the stem is badly corroded or the washer is not available, replacing the whole diverter kit is often the more reliable fix.

Test the Diverter

Turn the water on slowly. Switch the diverter to the showerhead and confirm that water flows only from the shower. Then switch back to the spout and check that the shower stops completely. Run the water for a minute in each position. If you still see leaks, recheck the washer seating and the alignment of the stem.

  • Plumber’s silicone grease: Helps rubber washers seal and slide without swelling or cracking. View on Amazon
  • Faucet cartridge and valve puller set: Removes stuck stems without damaging the surrounding brass. View on Amazon
  • Replacement tub diverter repair kit: Provides matched washers and seals so you do not have to guess at sizes. View on Amazon

Common Mistakes

  • Skipping the water shutoff, which leads to a messy spray when the stem comes loose.
  • Overtightening the retaining nut, which can crack the housing or make the diverter hard to move.
  • Mixing up washers or stems from different brands, since small differences affect the seal.
  • Using petroleum-based lubricant on rubber parts, which can cause them to swell.
  • Forgetting to photograph the parts before disassembly, which makes reassembly harder.

For more background on tub valve repairs, see How to Repair a Tub Faucet: A Step-by-Step Guide for Stopping Drips and Kohler Tub Faucet With Diverter: Step-by-Step Repair and Replacement Guide.

FAQ

Why does water still come out of the spout when the shower is on?

This usually means the diverter washer or stem is worn and not sealing against the spout port. Cleaning or replacing the washer typically fixes it.

Can I repair a diverter without removing the whole faucet?

Sometimes, if the diverter is a pull-up spout style. Most internal diverters require removing the handle and trim to access the stem.

When should I call a professional?

If the valve body is cracked, the pipes are corroded, or you cannot shut off the water supply, consult a licensed plumber before continuing.

Conclusion

A worn diverter is usually a simple fix once you identify the type and inspect the washer or stem. Clean the parts, replace anything damaged and test carefully before closing the wall. With the right part and a little patience, your tub will switch cleanly between spout and shower again.

Ready to choose one?

Caleb Morgan

About Caleb Morgan

Caleb Morgan is part of our editorial team and reviews and edits our kitchen faucets & sinks guides, checking product details against manufacturer specifications and owner feedback.