Plumbing

How to Replace a Faucet Cartridge

Stop a dripping single-handle faucet by identifying and replacing its cartridge correctly.

Common symptoms

• A faucet drips from the spout
• The handle is difficult to move
• Water temperature is difficult to control
• Water leaks around the handle

Likely causes

Start with the simplest observable cause and avoid replacing parts until the failure has been identified.

• Worn cartridge seals
• Mineral buildup
• A cracked cartridge body
• A damaged valve seat or retaining hardware

Tools and materials

• Hex keys
• Screwdrivers
• Adjustable wrench
• Cartridge puller if required
• Plumber’s grease

Step-by-step procedure

1. Plug the drain so small parts cannot fall into it. Photograph the handle and trim before disassembly.
2. Remove the decorative cap, handle screw and handle. Lift off the trim pieces while keeping them in order.
3. Confirm the faucet brand and cartridge model. Take the old cartridge to a plumbing supplier if identification is uncertain.
4. Remove the retaining clip or nut. Note the cartridge orientation before pulling it straight out.
5. Clean mineral deposits from the valve body without scratching the sealing surfaces.
6. Apply only a thin film of manufacturer-approved plumber’s grease to the new cartridge seals.
7. Install the cartridge in the same orientation, restore the retaining hardware and reassemble the handle.
8. Open the supply valves slowly, check operation and inspect for leaks.

Common mistakes to avoid

• Buying a visually similar but incompatible cartridge
• Twisting the valve body or supply lines while loosening parts
• Using petroleum grease on seals not designed for it

Verify the repair

Test the repaired component through several normal operating cycles. Watch, listen and feel for leaks, heat, movement, unusual noise or odour. Stop immediately if the condition worsens. Document the work and retain part numbers, receipts and manufacturer instructions for future maintenance.

When to call a professional

Call a plumber if the cartridge is seized, the valve body moves in the wall, or the faucet continues leaking after a confirmed correct replacement.

Editorial note

This guide is written for general homeowner education. Building codes, product instructions, warranties, condominium rules and licensing requirements vary. The safest compliant method for your property always takes precedence.