How to Fix a Leaking Cartridge Faucet

What You'll Need
Pipe wrench
Screwdriver Phillips head
Allen/hex wrench

Fixing a leaking cartridge faucet is a simple job that anyone can do with only a few of tools that you probably already have in your home. A leaking faucet is not only annoying, but it can waste money, especially in these times of water restrictions, environmental awareness and higher prices. 

Step 1 – Shut Off the Water

Shut of the water to the faucet. If you don’t have a shut-off tap under your bathroom or sink, you will have to shut off the water to your house at the main. This shut-off handle turns off clockwise. Sometimes this valve will be a toggle. 

Step 2 – Remove the Cover Plate

Turn the faucet to allow any residual water from pipe pressure to come out. This will save you from getting wet when you remove the handle.

The screw attaching the handle to the cartridge will probably be under a cover plate on the top of or under the handle, on the side. Remove the cover plate to expose the screw. 

Step 3 –Remove the Locking Nut

Loosen the screw. It may be a Phillips head screw or a hex/allen screw, so you should have both tools at hand. Lift off the handle after removing the screw. You should now see a locking nut which will be holding the cartridge down. Be aware that some types of faucet don’t have a locking nut, but most do.

Use the pipe wrench to remove the nut. Occasionally you may come across another screw, remove this also. Place all pieces in a safe place so you don’t knock them with an elbow or arm. 

Step 4 – Lift Out the Cartridge

Lift the cartridge and remove it. If it is stuck, use pliers to wriggle it free. You might find at this point that the O rings are worn and need replacing. Take the whole cartridge to the hardware store and the sales person will be able to advise you on the correct replacement O rings or cartridge. 

Step 5 – Replace the Cartridge

Fix on the new O rings, or just slip the new cartridge into the hole. Be sure to align the cartridge with the slots together with the housing. It will only go in one way so this is not hard.

After replacing the cartridge, replace and tighten the locking nut and re-install the handle. If you had to take out a screw holding the handle in place, reinsert and tighten it.

Turn on the water and check for leaks. 

Cartridge faucets rarely cause trouble, and are easy to replace as they only have one moving part, the stem inside that moves up and down as you turn the tap off and on. Usually you only have to replace the O rings, but it is very easy and cheap to replace the whole cartridge. If you are remodelling your bathroom, install cartridge faucets to save future problems.