How to Replace a Kitchen Faucet With an Air Gap

Knock-out holes around a sink's rim accommodate two-handled faucets and auxiliary hardware, such as air gaps and soap dispensers.

The small column that protrudes from the rim of many kitchen sinks, called an air gap, prevents a dishwasher's waste water from returning to the dishwasher's interior. Whereas standard dishwasher drain lines empty directly into a garbage disposal or drainpipe, a dishwasher drain line with an air gap connects to both the undersink drain assembly and the column mounted to the sink's rim. If dishwasher waste cannot enter the drainpipe or garbage disposal due to blockage, the waste water empties into the sink basin through the air gap's column, rather than returning to the dishwasher. You can easily replace kitchen faucets and dishwasher air gaps with standard hand tools.

Things You'll Need

• Rags
• Bucket
• Replacement air gap
• Adjustable wrenches
• Basin wrench
• Replacement faucet assembly

Instructions

1. Place rags or a bucket beneath the air gap's drain hose to catch any water that spills. Remove the air gap drain hose connection that connects the air gap to the dishwasher by wriggling the rubber connector or removing the hose's spring clamp.

2. Remove the hose's connection to the dishwasher. If you can't access the dishwasher's drain hose connection from below the sink, slide the dishwasher away from the counter to access its rear and remove the hose. Loosen and remove the hose connections that run from the air gap to the garbage disposal or drain assembly.

3. Loosen the nut that secures the air gap cylinder to the underside of the sink basin. Turn the nut counterclockwise to loosen it. Remove the nut and washer from the air gap cylinder and slide the cylinder out of the sink basin's knock-out hole. Replace the old cylinder with the new cylinder, slide the new cylinder's washer onto its shaft and attach the new nut to the cylinder to secure it to the underside of the sink basin.

4. Reconnect the dishwasher's drain hose to the dishwasher, air gap and garbage disposal or drain assembly. Move the bucket and rags beneath the faucet's supply valves. Turn the faucet's supply valves to the "Off" position. Remove the hot and cold water supply line connections to the faucet, using an adjustable wrench or a basin wrench. Allow any trapped water to drain into the bucket.

5. Loosen the nuts that secure the faucet assembly to the sink basin by hand or with a wrench. Remove the faucet's nuts and washers. Slide the faucet assembly out of the sink basin's knock-out holes. Replace the old faucet with the new faucet assembly. Most manufacturers supply rubber gaskets that seal and protect the underside of the faucet assembly; carefully follow your faucet manufacturer's instructions regarding the order of assembly.

6. Attach the replacement faucet's washers and nuts onto the threaded shafts that protrude from the underside of the sink basin. Tighten the nuts by hand or with a wrench. Connect the hot and cold water supply lines to the underside of the new faucet.

7. Tighten the supply lines' nuts by hand, and complete tightening them with a wrench. Turn the water supply valves to the "On" position and check the new connections for leaks. Check the dishwasher drain hose and air gap connections for leaks during the dishwasher's next drain cycle.

References

• City of San Jose: Tools for Repairing Faucets and Toilets
• King County: Water Discharge Diagrams