Cartridge faucets use up-and-down motion to regulate water flow and left-right motion to control temperature, their makers say. A faucet with two handles turning 90 degrees can be a cartridge faucet.

Use the twisting tool (a white plastic piece) that comes with your new Moen faucet to loosen the old cartridge. Then, insert the new cartridge into the faucet’s valve body – it is important that the ...