How to Winterize a Dishwasher in 5 easy steps

You might not think of a dishwasher as something that typically needs to be winterized, and in most cases, you’d be right. However, if you keep your dishwasher in an unheated location, you’ll need to properly prepare it for the winter months.

A non-winterized dishwasher can be severely damaged by being left in freezing conditions. To properly winterize a dishwasher, you need to make sure it is fully drained and cleaned, and you’ll need to fill it up with antifreeze.

In this article, we’ll be showing you how to winterize your dishwasher, and we’ll also share with you some other tips and information you might need to keep your dishwasher running well all year long.

Why Winterize a Dishwasher?

It’s not necessary to winterize a dishwasher in normal conditions, but it is if you plan on leaving your dishwasher in sub-zero conditions for any point in time. For example, if your dishwasher is located in a garage or a summer home that is not insulated, you’ll definitely need to make sure it’s winterized.

You need to winterize your dishwasher because any water that is still inside it can cause massive damage to the system if it freezes. If you’ve ever had pipes burst in your home during cold weather, then you know exactly how much this sucks.

As for why your pipes are at risk of bursting when the water inside them freezes, the problem isn’t caused by the ice itself, as you might expect. Rather, it has to do with increased water caused by the presence of ice.

When water turns to ice, the water molecules expand. This on its own isn’t enough to burst any pipes, though. Instead, the ice forces any unfrozen water up against the closed faucet or valve that the pipe is connected to.

As more ice forms, the unfrozen water is subjected to immense pressure between the ice and the faucet/valve. Eventually, the pipes burst due to this pressure, most commonly in an area where there is very little ice.

Generally, only the sections of the pipe downstream of the ice clog are at risk of bursting. The upstream sections of the pipe aren’t at as much risk because the water isn’t trapped and can usually go back to its source if it encounters a blockage.

Winterizing Your Dishwasher

Now, let’s go over how to properly winterize your dishwasher. The process of doing so isn’t too complicated, but you definitely need to do it right in order for it to actually work.

If you do everything correctly, winterizing your dishwasher should take no more than a few hours. Here’s what you’ll need to do:

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1. Prepare Your Dishwasher

Before you can really start winterizing your dishwasher, you need to prep it first. This involves making sure your dishwasher is totally empty and that the interior is clean.

  • To start, empty out any dishes or cutlery that are still inside the dishwasher
  • Remove the upper and lower dish racks as well as the cutlery basket.
  • Then, give the insides a wipe with a wet rag and some cleaning solution (or you can run your dishwasher’s self-cleaning cycle, if it has one). 

2. Disconnect Your Dishwasher From Its Water and Power Supply

Next, you need to disconnect your dishwasher from its supply of both water and power. You need to disconnect the water supply to ensure that no water remains in your dishwasher during the winter, and you need to disconnect the power supply in order to safely finish cleaning the dishwasher.

To turn off the water supply to your dishwasher, locate the water main in your home and turn it all the way off. You’ll probably need to drain the water from all of your pipes if your home isn’t winterized, so take this opportunity to run all the faucets in your house and flush all of the toilets until your pipes are as empty as possible.

You should also run your garbage disposal for a minute or so, since there’s a good chance that your dishwasher and your garbage disposal are hooked up to the same plumbing.

Now, disconnect the water supply hose to the dishwasher and allow as much water as possible to drain out from it. Then, disconnect the dishwasher’s drainage hose from your sink’s drain and do the same. 

It’s a good idea to have a bucket or a pan on hand when disconnecting these hoses to prevent water from spilling everywhere and making a mess. Once you’re done, you can reattach the supply hose to the dishwasher and the drainage hose to the sink. 

3. Thoroughly Clean Your Dishwasher

Now that you’ve disconnected your dishwasher from its power supply and have drained all of the water out of it, it’s time to do a bit of deep cleaning. This part may get a little gross, so we’d recommend having some dishwashing gloves on hand for this.

Under your dishwasher’s spray arms, you should see a little cylinder sticking up out of the bottom of your dishwasher. This is the cylinder filter, and you’ll have to remove it in order to clean it.

Related: Dishwasher not cleaning dishes on the top rack?

To remove the filter, simply hold onto it firmly and turn it counter-clockwise. This will release it from the base of the dishwasher. Empty out any loose bits of food caught in the filter, and if you have water to spare, give the filter a quick rinse. Then reinstall the filter.

Next, do the same with your dishwasher’s centrifugal filter and coarse filter. Check your dishwasher’s owners manual to find out where exactly these filters are located and how to remove them; the location of these filters can vary depending on what kind of dishwasher you have, and some of these filters might be under a plate that you’ll need a screwdriver to remove.

Related: Dishwasher Making Grinding, Humming or High-Pitched Noise?

Now, clean out your dishwasher’s sump. The sump is usually located near the cylinder filter, and is used to collect water for the dishwasher’s pump. Food can get trapped in the sump, and if enough gets trapped inside it’ll clog the sump up. Use your fingers to scoop up any debris you find in the sump (this is where dishwashing gloves will really come in handy).

Finally, check your drain valve to make sure that there’s no food bits inside it than will clog it up. Again, your drain valve’s location will vary depending on what model of dishwasher you have, so refer to your owner’s manual in order to find it.

Once you’ve found it, remove it from the dishwasher by unscrewing it. Check to see if there’s any bits of food caught inside, and if there are, rinse them out. 

At this point, your dishwasher should be totally drained and cleaned! 

4. Add Antifreeze 

Now that your dishwasher is complete, it’s time to add the antifreeze. The antifreeze will sit in the tubing throughout your dishwasher and prevent any small amounts of water that do remain from freezing up.

First, you need to get the right kind of antifreeze. Since you’re adding it to your dishwasher, where you’ll obviously be washing the plates and cutlery you use to eat, you’ll want to use a non-toxic antifreeze.

The best kind of antifreeze for this purpose is RV antifreeze, which is made for RV plumbing systems. This type of antifreeze uses propylene glycol as its main active ingredient.

Once you have the antifreeze you need, start by pouring about half a gallon of it into the basin of the dishwasher. Then, connect your dishwasher to a power supply again, and run a short wash cycle.

This will distribute the antifreeze throughout the tubing within the dishwasher. Wait a few minutes until you hear the dishwasher start its rinse cycle, and then once again disconnect the dishwasher from its power supply to stop it. If you’ve done everything correctly, the internals of your dishwasher should now be filled up with antifreeze.

Once you’ve shut the dishwasher off again, you may want to leave the dishwasher door open while you’re gone, to improve the air circulation inside it and prevent any mold or bad smells from occurring. It’s also a good idea to leave your dishwasher unplugged during this time, just in case.

Re: Why does my Dishwasher Smell?

5. Getting Your Dishwasher Operational Again

Once you return to your summer home or wherever your winterized dishwasher is, you can’t just use your dishwasher straight away. Even though the antifreeze in your dishwasher should be non-toxic, you don’t really want to give your dishes an antifreeze bath.

To get the antifreeze out of your dishwasher, turn the water supply to your home back on, and run your empty dishwasher for three to four full wash cycles. For the first wash cycle, you may want to add some detergent just to make sure that all the antifreeze inside is flushed out.

That’s basically everything you need to know about winterizing your dishwasher! In general, you should try to avoid storing any of your electrical appliances in temperatures below 40 degrees Fahrenheit or so, as low temperatures can sometimes damage electrical components. 

If you have to leave your dishwasher in sub-zero conditions, however, properly winterizing it will do a lot to protect it and keep it functional while it’s not being used. 

Reader Comments (9)

  1. By disconnecting the supply line from the inlet valve does all of the water that’s in there drain out? Would it be good to put a vacuum on the cut off valve side to remove
    water from the inlet valve and beyond?

    • Hi Chris,
      Are you trying to drain it completely? Using antifreeze instead will probably be the best option, if it’s practical for you. There’s really no way to be certain all of the water would be sucked out with a vacuum, though in theory that could work. However, any check valves and the like could be a problem.


  2. It’s difficult to acquire knowledgeable people about this topic, but the truth is be understood as there’s more you’re referring to! Thanks

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  4. Quite insightful post. Never believed that it was this simple after all. I had spent a very good deal of my time looking for someone to explain this topic clearly and you’re the only one that ever did that. Kudos to you! Keep it up


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