What Causes the Center Section of a Kitchen Faucet to Leak Underneath the Sink?

Supply Tubes

• Copper supply tubes are often connected to the kitchen faucet's body’s bottom extending down below the sink and countertop. The hot- and cold-water supply lines connect to the tubes, keeping the faucet readily supplied with water. See if either one or both of these connections are loose and leaking water. If one does leak, turn the corresponding shut-off valve completely to the right before loosening and then threading the nut that connects the tube with the supply line.

Spray Connection

• If the kitchen faucet is also outfitted with a side spray, the connection between the spray hose and the faucet might leak. Turn the shut-off valves underneath the sink all the way to the right, and then disconnect the spray hose from the faucet from underneath. Consult the faucet's owner's manual to see if pipe seal tape should be installed at the spray hose's connection to the faucet. If so, wrap two loops of the tape around the threads and reinstall the spray hose to the faucet.

Missing Gasket

• Some kitchen faucet models come equipped with a rubber gasket, also called a rubber escutcheon, that fits onto the faucet’s bottom, creating a seal between the faucet and sink. If the gasket is not used, water leaks between the faucet and sink, as well as directly underneath the sink. Replace the gasket if it is faulty and allowing the leak. Install a gasket underneath the faucet body if there is none, or else use plumber's putty underneath the faucet body serving as a watertight seal.

Faucet Corrosion

• Faulty main parts within the faucet could cause the leak. This is most likely to happen on an older faucet, whose inner parts have corroded. If this is the case, the replacing the faucet with a newer model is simple.