You clean a dishwasher air gap by pulling or twisting off its cap, removing the inner cover, clearing debris from the opening, and flushing the hose that runs from the air gap to the drain or disposal. It's the fix when water spurts out of the small fixture beside your faucet during a dishwasher drain, or when the dishwasher empties slowly.
Time: about 20 minutes · Difficulty: Moderate · You'll need: a bottle brush or pipe cleaner, a flashlight, a small bucket, towels, pliers (optional)
Before you start
- •Make sure the dishwasher isn't running or draining.
- •If your dishwasher drains through a garbage disposal, switch the disposal off at its wall switch (or unplug it under the sink, if it plugs in) before reaching anywhere near it. Never put your hand inside a disposal.
- •Clear out the sink cabinet and lay towels down, since the hoses may hold some dirty water.
Steps
Step 1 — Confirm you have an air gap
An air gap is a small cylinder, usually chrome or white, mounted on the sink deck or countertop near the faucet. Underneath, two hoses connect to it: one from the dishwasher and a larger one running to the disposal or sink drain.
Step 2 — Remove the cap and inner cover
The decorative cap usually pulls straight up or twists off. Under it there's often a small plastic cover that unscrews by hand or with gentle pliers.
Step 3 — Clear the opening
Shine a flashlight into the air gap and pull out any food, grease or sludge with a bottle brush or pipe cleaner. Run a little water through to see if it drains down easily.
Step 4 — Check the outlet hose
Under the sink, find the larger hose from the air gap to the disposal or drain. Loosen its clamp, pull it off over a bucket, and flush or brush it clear. Look for kinks or sags that hold food.
Step 5 — Run the disposal (if you have one)
With the hose back on and clamps tight, run the disposal with cold water for a few seconds. A full disposal can block the dishwasher's drain path.
Step 6 — Reassemble and test
Replace the inner cover and the cap. Run a short dishwasher cycle and watch the air gap during the drain portion.
Didn't fix it?
If water still spits out, the blockage is further downstream. A common one shows up right after a new disposal goes in: the disposal's knockout plug for the dishwasher inlet wasn't removed, which a plumber or technician can confirm. A clogged sink drain line is plumber territory. If the drain path is clear and the dishwasher still won't empty, the drain pump may be failing; have our dishwasher repair team test it. A clogged filter also slows draining, so see how to clean a dishwasher filter if you haven't checked it.
How often to do this
Check the air gap every few months, and whenever you notice slow draining. Running the disposal until it's clear before starting the dishwasher helps keep the shared drain path open.
From Kevin: Water bubbling out of the air gap looks alarming, but the air gap itself is usually doing its job. It's telling you the drain line after it is blocked, and that's where to look.
Call ProFix NJ at (973) 718-9373 if the water keeps coming back.