Caleb MorganBy Caleb Morgan

Updated November 2026

To repair a leaky faucet in bathtub, you shut off the water, remove the handle and trim, pull out the valve cartridge or stem, and replace the worn part that is causing the drip. Most bathtub leaks come from a worn cartridge, a failed washer, or a damaged seat, and each can be swapped with basic hand tools in under an hour. This guide walks through the process for the most common single-handle and two-handle designs.

Before You Start: Shut Off the Water and Identify the Leak

Shut off both the hot and cold supply valves, usually located behind an access panel or in the wall near the tub. Then open the tub faucet to drain residual water. Check whether the drip comes from the spout or from the showerhead diverter, since a diverter leak needs a different fix. Mark which handle or control leaks so you can match the replacement part correctly.

How to Repair a Leaky Faucet in Bathtub: Removing and Replacing the Cartridge

Most modern tub faucets use a cartridge. Once you know which part is leaking, follow these steps to swap it out.

  1. Pry off the decorative cap on the handle with a flat-blade screwdriver, then remove the handle screw.
  2. Unscrew the trim plate or escutcheon and pull the handle assembly free.
  3. Remove the retaining clip or nut that holds the cartridge, then pull the cartridge straight out with pliers, using a rag to protect the finish.
  4. Compare the old cartridge to the replacement. Match the brand, model and length before buying or installing.
  5. Insert the new cartridge with the index tab or notch aligned as the original was, then reinstall the clip or nut.
  6. Reassemble the handle, restore the water supply slowly, and test both hot and cold for drips.

Replacing Washers, Seats and Stems on Older Faucets

Older compression faucets leak from worn washers and O-rings rather than cartridges. Remove the handle and packing nut, unscrew the stem, and replace the rubber washer at the base. If the seat inside the valve body is pitted, a seat wrench can resurface or replace it. Use a stem or seat kit that matches the faucet brand, since dimensions vary between manufacturers. Owners often report that replacing only the washer stops the drip for a few months before the seat wears again, so inspect both at the same time.

Checking for Hidden Causes

If the drip continues after the cartridge or washer is replaced, check the diverter for debris and confirm the supply valves are fully open. Mineral buildup can keep a cartridge from seating, so flush the valve body with clean water before reinstalling parts.

  • A cartridge puller or basin wrench helps remove stubborn parts without scratching the finish. View on Amazon
  • Plumber’s silicone grease keeps O-rings and cartridges moving smoothly and reduces future wear. View on Amazon
  • A seat wrench lets you pull or resurface worn valve seats on compression-style tub faucets. View on Amazon

Common Mistakes to Avoid

  • Buying a part without confirming the brand and model, which leads to a cartridge that fits poorly and keeps leaking.
  • Forcing the handle or cartridge without removing the retaining clip first.
  • Reinstalling a cartridge with the index tab misaligned, which can cause hot and cold to reverse.
  • Skipping the water shutoff and getting sprayed during removal.
  • Overtightening the handle screw, which can crack the new cartridge housing.

For more model-specific help, see Delta Bathtub Faucet Repair Kit: Step-by-Step Fix for Leaks and Drips and Delta Bathtub Faucet Cartridge: How to Replace One in 6 Steps. If you are unsure which replacement part you need, 5 Best Leaky Faucet Repair Bathtub Kits for Common Leaks and Drips (2026) compares common kits. For a Kohler model, Kohler Artifacts Bathtub Faucet: Identify, Repair and Maintain It (Step-by-Step) covers identification and repair.

FAQ

Why does my bathtub faucet keep dripping after I replace the cartridge?

The new cartridge may be the wrong size, or it may be seated with the index tab misaligned. Debris or mineral buildup in the valve body can also prevent a tight seal, so flush the valve before reinstalling.

Do I need to replace the whole faucet to stop a leak?

Usually not. Most leaks come from a worn cartridge, washer or seat, and those parts can be replaced individually. A whole faucet replacement is only necessary if the body itself is cracked or corroded.

Should I hire a plumber for this repair?

Many homeowners can handle a cartridge swap with basic tools. If the valve is seized, the pipes are corroded, or you suspect a leak inside the wall, consult a licensed plumber to avoid water damage.

Conclusion

Shutting off the water, identifying the faulty part and replacing it with a matching cartridge, washer or seat will stop most bathtub faucet leaks. Take photos as you disassemble so reassembly is straightforward. If the drip persists after repair, recheck the part fit and the diverter before assuming a bigger problem.

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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.