Caleb MorganBy Caleb Morgan

Updated November 2026

To repair a bathtub faucet diverter, you will identify whether the diverter is a pull-up, push-button or lever type, shut off the water, remove the diverter cap and stem, and clean or replace the worn washer, seal or cartridge. Most diverter failures come down to a worn rubber seal or mineral buildup, and both are fixable with basic hand tools. This how-to-repair-bathtub-faucet-diverter guide walks through the process from start to finish.

Identify Your Diverter Type First

Before you take anything apart, confirm which kind of diverter your tub has, because each one comes off differently. A pull-up diverter is a knob on the spout you lift to send water to the showerhead. A push-button diverter sits on the spout or handle and is pressed in. A lever diverter is part of the handle assembly and rotates to redirect flow. Many Delta and Moen tub faucets use a pull-up style, while some Kohler models use a diverter built into the valve body.

If water keeps coming out of the spout while the shower is running, or the shower only trickles, the diverter is usually the culprit rather than the cartridge.

Step-by-Step Diverter Repair

  1. Shut off the water supply to the tub, or turn off the main if you cannot find local valves. Open the tub faucet to drain any remaining water.
  2. Pry off the decorative cap or set screw cover with a flat screwdriver or a small knife. Remove the screw underneath.
  3. Pull the diverter stem or knob straight off. If it sticks, apply a little penetrating oil and wait five minutes before trying again.
  4. Inspect the rubber seal or O-ring on the diverter stem. Look for cracks, flattening or grit. Replace it if it looks worn.
  5. Clean the diverter seat inside the spout with a soft cloth and white vinegar to dissolve mineral deposits. Avoid steel wool, which can scratch the finish.
  6. Lubricate the new or cleaned seal with silicone plumber’s grease, then reinstall the stem and tighten the screw snugly without overtightening.
  7. Turn the water back on slowly and test both the spout and shower positions.

When the Problem Is Inside the Valve

If the diverter seal is fine but water still leaks into the spout, the diverter valve or cartridge may be worn. In that case, the valve body needs a closer look, and a matching repair kit is usually the better fix. Manufacturers such as Delta and Moen publish parts diagrams for their models, so match the diagram to your faucet before ordering parts.

Repair Parts Checklist

  • Flat-head screwdriver and Phillips screwdriver
  • Adjustable wrench or basin wrench for stubborn nuts
  • Replacement diverter seal or O-ring matched to your model
  • Silicone plumber’s grease
  • White vinegar and a soft cloth
  • Towels or a bucket to catch residual water
  • Silicone plumber’s grease helps seals slide smoothly and resist wear. View on Amazon
  • Faucet repair kit for tub diverters gives you matched seals and springs for your brand. View on Amazon
  • Penetrating oil loosens stuck diverter stems and corroded screws. View on Amazon

Common Mistakes and Tips

  • Forgetting to shut off the water, which can cause a sudden spray when the stem comes loose.
  • Using petroleum-based grease on rubber seals, which can cause them to swell and break down. Stick with silicone-based lubricant.
  • Overtightening the diverter screw, which can crack the spout or strip threads.
  • Replacing the wrong seal size. Measure the old O-ring or bring it to the store.
  • Skipping the test after reassembly. Check every diverter position before closing the wall access.

Troubleshooting Diverter Leaks

If the tub spout drips after you have replaced the seal, the problem is often in the valve body rather than the diverter itself. Our How to Repair a Leaky Tub Faucet: A Step-by-Step Guide article covers how to diagnose valve-side leaks. For a complete parts-level walkthrough on a common brand, see How to Replace Delta Bathtub Faucet Parts: A Step-by-Step Guide. If you have a Kohler model, Kohler Tub Faucet With Diverter: Step-by-Step Repair and Replacement Guide explains the design differences. For a leaking tub spout that is not related to the diverter, Repair Bathtub Faucet Leak: A Step-by-Step Guide to Stop Drips is a useful next read. If you prefer a ready-made solution, Bathtub Faucet Diverter Repair Kit: 6 Best Picks for Leaks (2026) lists options worth considering.

FAQ

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

This usually means the diverter seal is worn or mineral buildup is preventing it from sealing fully against the spout. Cleaning the seat or replacing the seal typically solves it.

Can I repair a bathtub diverter without removing the faucet handle?

Many pull-up and push-button diverters can be reached from the spout alone. Lever-style diverters often require removing the handle, so check your model before starting.

Should I call a plumber for a diverter repair?

Diverter seal replacement is a manageable DIY job for most homeowners. If the valve is corroded, the wall is damp, or you find signs of water damage, consult a licensed plumber.

Conclusion

Repairing a bathtub faucet diverter usually means identifying the type, cleaning or replacing the seal, and testing every position before you finish. With a few basic tools and matched parts, most homeowners can restore proper shower flow in an afternoon. If the leak continues after the diverter is fixed, check the valve body before replacing more parts.

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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.