4 March, 2022
How to Connect a Dishwasher to a Drain
If you’ve got a built-in dishwasher in your kitchen, it’s vital to connect the drain hose that comes with it. Dishwasher drain hoses can either be connected to the sink’s drain assembly or the garbage disposal, depending on whether your dishwashing machine has a garbage disposal.
First, you’ll need to disconnect the existing water supply line under the sink. You’ll also need a new dishwasher connector kit with a braided steel water supply hose and a 90-degree fitting.
Using a wrench, remove the old water supply line from the shut-off valve under the sink and replace it with the new one. Alternatively, you may need to install a three-way shut-off valve that is attached directly to the hot-water supply line. Then, thread the coupling nut onto the 90-degree fitting and tighten it with channel-lock pliers or an adjustable wrench.
The next step is to route the hose through the hole between the sink cabinet and the dishwasher. The hose should make an arch higher than the drain inlet to prevent backwash from the sink drain. Secure any slack in the hose to the underside of the sink cabinet with a hose bracket.
Once you’ve positioned the hose correctly, attach it to the drain trap under the sink. You can do this by looping it up to the underside of the countertop or by attaching it to an air gap fitting mounted on the counter or sink deck. The air gap device will pull in air to keep the drain hose from being sucked back into the dishwasher, reducing the risk of sewer gases backing up in the appliance.
You can then attach the hose to the garbage disposal or sink drain tailpiece with a hose clamp, either of which should be the appropriate size for your application. If the hose is too long, you can cut it to make it easier to fit with the nozzle on the dishwasher’s tailpiece.
Now, you’ll need to connect the hose to the drain inlet on the dishwasher. Most hoses come with a rubber boot, which lets you connect it to a variety of connections, including 1/2-inch, 3/4-inch and 1-inch.
Most dishwashers also feature a basket-shaped element that fits in the drain hose and is removed when not in use. It’s essential that you don’t forget to remove the hose when not in use and then clean it out before reattaching it to the sink.
It’s also a good idea to check the hose before you turn on the dishwasher and ensure that it hasn’t been clogged. It’s usually possible to get a cleaning agent or a de-clogging tool that will unclog the hose.
If your sink does not have a garbage disposal, you’ll need to connect the dishwasher drain hose to the drain port on your sink’s drain assembly. To do this, you’ll need a power drill and an appropriate hole saw or drill bit. If there’s no hole already in your sink, create a 1-1/2-inch hole with the hole saw or drill bit. Once the hole is drilled, insert the new dishwasher drain hose into the hole, and secure it with a stainless-steel hose clamp.