How to Install a Dishwasher: A Step-by-Step Guide
Before you make this investment, though, make sure your current dishwasher really needs to be replaced. For starters, give it a good cleaning using a high-quality detergent. Then, double-check that you’re loading it the right way. Run a couple of loads and see. Still having to do a wash afterward? It’s probably worth upgrading.
How to Add a New Dishwasher to a Kitchen
Hooking up a new appliance with This Old House plumbing and heating expert Richard Trethewey.
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1 out of 5 Easy Only basic plumbing skills required
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In this video, This Old House plumbing and heating expert Richard Trethewey hooks up a new dishwasher.
Steps for Installing a New Dishwasher
- Shut off the water to the kitchen sink.
- Use a wrench to remove the existing shut-off valve on the hot-water supply line under the sink.
- Install a new three-way shut-off valve onto the existing hot-water supply line.
- Reconnect the hot-water supply line to the new shut-off valve.
- Connect a stainless steel braided water-supply hose to the shut-off valve.
- Remove the existing tailpiece attached to the sink’s basket strainer and replace it with a dishwasher tailpiece. Tighten the threaded connections with pliers.
- Tip over the dishwasher and lay it on its back on top of a canvas tarp.
- Wrap Teflon tape around the male threads of a brass adapter elbow.
- Thread the elbow into the water-inlet port on the front of the dishwasher. Carefully tighten the elbow with an adjustable wrench.
- Make the electrical connection to the dishwasher with a polarized appliance plug. Secure the wires with twist-on wire connectors.
- Extend the stainless steel braided water-supply hose from the sink cabinet out to the dishwasher. Tape the hose down to the floor with electrical tape. 12. Carefully slide the dishwasher into place.
- Connect the water-supply line to the dishwasher.
- Use a drill/driver to screw the dishwasher’s mounting tabs to the underside of the countertop.
- Adjust the leveling legs with a wrench until the dishwasher is perfectly level. Replace the dishwasher’s front panel.
- From inside the sink cabinet, connect the discharge hose from dishwasher to the dishwasher tailpiece.
- Turn on the water, plug in the dishwasher’s power cord and test your work.
How to Install a Dishwasher: A Step-by-Step Guide
If your new dishwasher doesn’t come with free installation, you might be able to save some money by installing it yourself.
Maybe you’ve never had a dishwasher and you’re ready to give your kitchen an upgrade. Or maybe your current model just isn’t doing the job you need. In any case, you know that getting a new dishwasher means spending some cash (the best ones run you around $1,000).
After that sizable purchase, you probably don’t want to shell out anymore, so you might be thinking about trying to install your dishwasher yourself. Good news: You absolutely can. We’re here to give you a step-by-step guide to getting your new kitchen appliance up and running.
Before you make this investment, though, make sure your current dishwasher really needs to be replaced. For starters, give it a good cleaning using a high-quality detergent. Then, double-check that you’re loading it the right way. Run a couple of loads and see. Still having to do a wash afterward? It’s probably worth upgrading.
Here’s everything you need to know to install a dishwasher in your kitchen, in step-by-step order.
1. Pick the right dishwasher
Since a dishwasher is an investment, you’ll want to make sure you’re putting your money into something that will give you sparkling-clean dishes for years to come.
As you’re shopping, consider the features you might want — like a dedicated place for your wine glasses or a third rack for your flatware.
Then, think through other key buying factors, like:
- Noise level
- Cycle options, like express cleaning or rinse-only
- Efficiency (fortunately, virtually any dishwasher will save water over hand washing)
- Finish
Don’t rush this decision. Do your homework and pick the dishwasher that’s right for you.
2. Get your old dishwasher out (if applicable)
Safety (and mess-avoidance) first: Turn off electricity to the dishwasher at your circuit breaker and turn off the water supply using the valve under the sink.
At the bottom of your dishwasher, you should see a front access panel. Take this off using a screwdriver.
Disconnect the wiring connections and the water supply. The latter will probably have water in it, so have a bowl and some rags handy. Disconnect the drain hose, too.
Now, detach the dishwasher from any anchor points. These are usually located on the underside of your counter and the adjacent cabinets.
Finally, reach under the bottom of the dishwasher. It has four leveling legs that keep it flush with the top of the counter. Using pliers, adjust those to lower the dishwasher so you’ll be able to pull it out.
Before you give it a tug, put some cardboard (the box from your new dishwasher will work) or an old blanket down so you don’t scratch up your floor.
3. Hook up water, power and the drain hose
If you didn’t have an old dishwasher to remove and skipped that step, now’s the time to turn off the electricity (at your circuit breaker) and water (at the valve under your kitchen sink). You might also need to drill holes in the cabinet between where the dishwasher will go and the area under your sink. This will let you run the power cord, water supply and drain hose through.
Position your dishwasher near the gap where it will be installed and take off the front access panel. Depending on where the connections are, you may want to carefully lay it on its back for easier access.
Now, it’s time to connect the three main pieces your dishwasher needs to run:
Electrical: Identify the wire connection housing. It likely has a cover you’ll need to remove. Your dishwasher comes with a power cord — thread the end you don’t plug into an outlet into there. Connect the wires to the respective wires of the same color (e.g., green to green, white to white, black to black). Replace the wire housing cover. Thread the cord under your sink and plug it in.
Water supply: Your dishwasher probably came with a small, 90-degree fitting that connects to the back of the unit, letting the water supply line extend parallel to the back of the dishwasher. Attach that first. Then, connect the water supply line that your dishwasher came with from the valve under your sink, through the hole in your cabinet, to that piece on the back of your dishwasher.
Read the manufacturer’s instructions. Many dishwasher water supply connections are compression fittings, but you might need joint compound to get a leak-free fit. Add joint compound, if needed, and tighten the water supply line to the dishwasher and to the water connection under your sink by hand. Then, grab a wrench and give them a quarter-turn for a tight fit. Don’t over-tighten or you could strip the threads.
Drain hose: Finally, connect the drain hose to your dishwasher if it wasn’t already. Feed the attached drain hose from the dishwasher through the hole in your cabinet. Connect it to either your sink tail pipe or your garbage disposal unit. Follow the manufacturer’s instructions. You may need to loop the hose up to create an air gap that stops dirty water from feeding back into the dishwasher.
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4. Get the dishwasher in place
Now, if you put the dishwasher on its back, carefully tip it so it’s right side up. Slowly and carefully push it into the space under your counter.
You may want to have a second person pull the power cord, water supply and drain hose through the hole in your cabinet as you do this to ensure any slack doesn’t get caught under the dishwasher. You can feed any excess back behind the dishwasher once it’s in place.
5. Test it out
Before you do all the fiddly work of getting your dishwasher perfectly positioned and anchored, run a full cycle. Don’t forget to turn the water and power back on first.
If the dishwasher turns on, great — you at least got the electrical connections right. If it doesn’t, you may want to call a local electrician to come help you out.
As it runs (and afterward), check for leaks. Tighten any connections as needed, working in small increments to avoid over-tightening.
6. Level and anchor it
Once you’re sure the dishwasher is working like it’s supposed to, grab some pliers. Use those to adjust the legs under the dishwasher so that it’s flush with your countertop. Grab your level to confirm it’s flat or you could run into problems with drainage.
Finally, grab the brackets it came with and use those to anchor the dishwasher to the underside of your cabinet and the adjacent cabinets.
Lastly, put the front access panel back on.
Monitor your work
Nice work. But keep an eye on things. If you notice any leaks and can’t seem to get things tight enough, call a plumber before you strip its connections by overtightening.
Once your dishwasher functions like it should, put it to work for you. You don’t have to stop at dishes.