dishwasher vent

Air gaps are the most effective means of preventing your drain from cross-contaminating your dishwasher with waste. If you want to protect your dishwasher from flooding with contaminated water, you need an air gap. Dishwasher air gaps are also required by plumbing codes in many locations.

What is the dishwasher vent for?

What Is Dishwasher Venting? Dishwasher venting prevents dirty water from re-entering the dishwasher. There are several common ways to do this: creating a high loop in the drain hose, connecting the hose to an air gap fitting, or installing a check valve on the drain line.

Where is the dishwasher vent?

Follow the dishwasher manufacturer’s recommendations regarding where to locate the dishwasher vent. Usually it is installed on your counter, next to the sink on the side closest to your dishwasher.

Why does a dishwasher need an air gap?

This will help prevent a clogged sink drain from causing dirty water to gravity-flow back into the DW through its drain line. An air gap is preferable as activating a disposal while there is a clog in the sink drain can still cause back-flow into the DW.

Why does my dishwasher drain out the vent?

Answer: The air gap is just that – a gap of air in the dishwasher drain line so dirty water can not be forced up out of the sink and into the dishwasher. When the gap leaks, it is normally due to a kink or blockage in the tube from the air gap to the tail piece (drain line) below the sink.

What happens if your dishwasher doesn’t have an air gap?

If your dishwasher doesn’t have an air gap, its drain hose may be looped up and attached to the bottom of the countertop near the sink. Although this is not code-compliant in most places, it serves the same purpose as the air gap—to prevent drain water from siphoning back into the dishwasher.

Do dishwashers have backflow prevention?

Some dishwashers contain one-way drain valves that prevent backflow, but others depend on a simple installation trick. Local building codes might require a separate backflow preventer at the sink.

How do I know if my dishwasher vent is working?

Some dishwashers use a vent fan motor to help dry the dishes at the end of the cycle. If the fan motor is not working, the dishwasher won’t dry the dishes properly. To determine if the fan motor has failed, test the motor for continuity. Also, try turning the fan blade by hand to ensure that it spins freely.

What can I use instead of an air gap?

If your sink lacks an available hole for installing an air gap, a plumber can usually drill an opening where needed. Another way to provide a hole is to replace the standard type sink faucet with a post-type faucet, one that does not have the rectangular mounting plate at its base.