Buying a dishwasher from a dedicated outlet often means the connections would be done by the delivery team, and they may even haul away the old one.
However, if you buy a dishwasher from an online retailer or big-box home improvement store, you may have to pay a substantial charge for its connection since it normally is not included in the price.
The good news is that it is fairly easy to connect a dishwasher yourself.
Three Mechanical Connections
Three connections are required to hook up a new dishwasher: power, water supply, and drain line connections.
All of these can be done by DIYers who understand the requirements.
It may be a bit tricky to connect the power cable, particularly if you have no electrical wiring experience.
“Hard-wiring” can be done on dishwashers using an NM circuit cable which runs directly into its connection box.
Alternatively, the more common connection of a standard appliance cable plugged in a wall outlet unit.
Wiring a dishwasher yourself is absolutely easy. Both connections (hard-wired and appliance cable) are exactly similar, having wire connections within an access panel at the appliance base.
Connecting the water supply is as simple as attaching an end of a supply tube of braided steel to the dishwasher water inlet valve and the other end of the supply tube to the hot water supply pipe shutoff valve.
The supply tube here is simply a longer kind of the same supply tube which feeds toilets and faucets, so you should have no issues connecting the dishwasher if you have experience working on those fixtures.
Drain hose connection is equally simple for a dishwasher.
This hose is connected to the drain tap underneath your sink and loops up into an air-gap fitting.
Upon looping back down, the drain hose is connected directly to the sink drain or the garbage disposal.
Connect the Electric Cable
In a dishwasher installation the majority of the functional parts – both plumbing and electrical connections – can be found within an access panel that is at the bottom of the front side of the dishwasher.
Although these connections can be made while you lie on the floor or crouch, it is easiest for many people to lay the dishwasher carefully on its back and remove the panel to make the initial connections.
Begin by removing the access panel at the bottom of the dishwasher. Look out for the fittings for power cable and the drain, as well as the solenoid water inlet valve.
Take note: If access holes have not already been drilled at the base cabinet side, you’ll have to do it so that the power cable can be run to the outlet and the drain hose to the sink drain or garbage disposal.
Remove the wire connection board cover.
Have the power cable threaded into the board, and carry out the following wire connections:
- Connect the appliance cable green wire to the green grounding screw
- Attachwhite (neutral) wire to the white dishwasher lead
- Connect the black (hot) wire to the black dishwasher lead
These connection are typically done with wire nuts (twist-on wire connectors), but the methods may be different for some appliances. Reattach the wire connection board cover.
Connect the Water Line
In a dishwasher installation a 90 degree fitting is included in your connector kit to hook up the water supply. The first step here is to install the dishwasher 90.
On the solenoid valve, identify the fitting for water inlet.
Smear the dishwasher 90 threads with pipe joint compound, and then thread it into the solenoid valve.
Use your hand to tighten it fully, and then use an adjustable wrench or channel-lock pliers to tighten an extra quarter turn.
Also included in the connector kit is a water supply tube of braided steel.
Thread the supply tube’s coupling nut into the dishwasher 90, and use an adjustable wrench or channel-lock pliers to tighten it.
This compression fitting does not need pipe joint compound. Ensure not to over-tighten so the threads don’t get stripped.
Position the Dishwasher
Turn the appliance right side up and position it beneath the kitchen counter, running the power cable, drain hose, and water supply line through the holes at the cabinet sidewall.
Move the dishwasher up to the middle of the opening, not pushing it back too far.
Adjust the dishwasher level using the adjustable legs according to the manufacturer’s guide.
If necessary, the legs can be unscrewed with pliers to match the dishwasher installation to the height of the counter.
Secure the Dishwasher
Once your dishwasher is successfully positioned, you can fasten it in place.
Access the mounting brackets within the dishwasher door.
Using the screws given, have the brackets fastened to the frame of the cabinet under the counter lip.
Attach Water Supply
Attach the water supply tube end to the shutoff valve underneath the kitchen sink.
(A new dishwasher installation may require you to install a hot-water pipe shutoff valve.)
Check for leaks on the shutoff valve by turning it on.
Also check for leaks underneath the dishwasher at the supply tube end connecting to the dishwasher 90 fitting.
If any leaks are noticed at either end, softly tighten it a bit more.
Attach the Drain Hose
In most cases, the dishwasher comes with a rubber drain hose already attached. Otherwise, it can easily be attached using a hose clamp.
Various possible settings exist for the drain hose, subject to your sink settings and local code:
The drain hose of the dishwasher can be connected to an air-gap fitting positioned on the sink deck or countertop.
This fitting allows air into the drain hose, preventing the siphoning of wastewater back into the appliance.
Another hose runs from the sir-gap to a nipple, either on the side of the tailpiece of the sink drain or on the garbage disposal.
You may loop up the drain hose of the dishwasher and secure it underneath the countertop, then drop it back down to be attached to a nipple on the tailpiece of the sink drain or the garbage disposal.
Similar to an air-gap, the “high loop” serves to prevent the siphoning of wastewater back into the appliance.
However, this method may not be permitted by local codes.
Test the Dishwasher
Plug in the power cable of the dishwasher. Run a complete cycle on the dishwasher installation to test it before covering the front of the appliance with the face-plate.
Ensure that fresh water is supplied and the drain water flows properly, without any leaks at the connections.
Finally, replace the face-plate at the dishwasher front base.
Next up is our article on the best drain cleaner.