Types of Bathtub Faucets

  • Single-handle faucet: One lever controls both temperature and flow — usually uses a cartridge
  • Double-handle faucet: Separate hot and cold handles — uses cartridges or compression valves
  • Three-piece set: Separate hot, cold and spout — each handle is independent
Before startingTake photos of all connections before disassembly. Bathtub faucet installation varies significantly by brand and type. If you encounter anything you are not sure about — stop and call a licensed plumber. Water damage from plumbing mistakes is expensive to repair.

Replacing a Cartridge-Based Faucet

  1. 1

    Turn off the water supply

    Find the isolation valves under the bath or in the access panel (usually behind the bath panel, in a cupboard, or in a wall void behind the taps). Turn both hot and cold valves clockwise until closed. Turn the tap fully on to release remaining pressure.

  2. 2

    Remove the handle

    Prise off the decorative cap on the handle with a flat screwdriver. Remove the screw underneath. Pull the handle straight off — it may need gentle persuasion if corroded.

  3. 3

    Remove the trim sleeve and escutcheon

    The decorative sleeve and plate around the valve may unscrew or clip off. Remove to expose the valve body.

  4. 4

    Unscrew the retaining nut and remove the cartridge

    Use an adjustable spanner to unscrew the retaining nut (anticlockwise). Pull the cartridge straight out — it may need firm pressure. Note the orientation carefully (photograph it).

  5. 5

    Match and replace the cartridge

    Take the old cartridge to a plumbing supplier to match exactly — cartridges are brand-specific and not universal. Insert the new cartridge in the same orientation as the old one. Refit the retaining nut and trim.

  6. 6

    Turn water back on slowly and test

    Open the isolation valves slowly. Check for leaks at the valve body and spout. Test temperature and flow. Tighten fittings if any dripping occurs.

Full tap replacement vs cartridge replacementIf the tap body is very old, corroded, or you want a new look — replacing the entire faucet assembly makes more sense than just replacing the cartridge. This is more involved as it requires disconnecting the water supply lines and removing the old faucet body from the bath. Achievable DIY but more complex — look up a specific tutorial for your tap brand and bath type.

Frequently Asked Questions

Replace just the cartridge if: the tap drips from the spout, the handle is stiff or hard to turn, or temperature control is poor — these are all cartridge wear symptoms. Replace the whole tap if: the body is cracked or corroded, there is leaking from the base that the cartridge does not fix, you want a different style, or it is a very old compression-type valve that is no longer worth maintaining.
Call a plumber if: you cannot locate or turn off the isolation valves, there is corrosion or damage to the water supply pipes, you have a concealed in-wall mixer system, or after replacing the cartridge the tap is still leaking. Some bath tap systems are built into the wall with concealed valves — these are definitely plumber territory.