Does a Dishwasher Use Hot Water?

By Nick Evans •  Last Updated: 09/01/21 •  4 min read

Have you ever wondered whether your dishwasher uses hot water, or heat up by itself? Maybe your dishwasher isn’t working properly and you’d like to get to the source and avoid having to hand wash your dishes!

We’re here to help. In this article, we’ll go over:

  • Do dishwashers use hot water or heat their own?
  • Will a dishwasher work without hot water?
  • Does a dishwasher use a lot of hot water?
  • Why is my dishwasher using only cold water?
  • Does a Bosch dishwasher use hot or cold water?
  • Do Whirlpool dishwashers heat their own water?
Does a Dishwasher Use Hot Water

Do Dishwashers Use Hot Water or Heat Their Own?

Whether your dishwasher heats its own water will depend on its brand and model.

Dishwashers sometimes use hot water from a hot water valve, typically located beneath your sink. This supplies hot water to the dishwasher, but that isn’t always the end of the process.

Many dishwashers take the hot water and heat it further to ensure your dishes are properly cleaned and sanitized.

Some dishwashers can even heat water from a cold water valve. Check your manual to see if this is the case for your model.

Otherwise, we don’t recommend washing dishes with cold water. While you can do so, hot water is better able to break through the grime, sanitize your dishes, and rinse away the dishwasher detergent.

Will a Dishwasher Work Without Hot Water?

All dishwashers can run without hot water, but we only advise doing so with dishwashers that heat their own water. Check your manual to see whether or not your dishwasher can be run with cold water.

A dishwasher that doesn’t heat its own water can also run with cold water, but it’s not advised.

Cold water will not clean your dishes properly, and will leave residue such as food, dish soap, and other debris behind.

Does a Dishwasher use a Lot of Hot Water?

A dishwasher does use a lot of hot water, but not as much as hand-washing your dishes. Modern dishwashers use about 3 gallons of water each cycle, compared to 27 gallons when hand washing the same amount of dishes.

Older dishwasher models use much more water, so a good way to cut down on your water consumption (and lower your water bill!) is to upgrade to a newer model if you haven’t yet.

Although more water-efficient appliances typically cost more, they do save you money over time as you spend less on your water and electric bills.

Why is my Dishwasher using only Cold Water?

Do you suspect your dishwasher is only using cold water instead of heating the water properly? Here’s how to tell:

The most common fix for this problem is to replace the heating elements on your dishwasher. Likely, they aren’t working properly and that’s why your dishes aren’t coming out shiny-clean like you expect.

Your hot water line may be the source as well. If the line isn’t working properly, your dishwasher won’t receive the hot water it needs to run a cycle.

The last solution is to hire a professional. They can identify the problem, which may be the timer or thermostat on your dishwasher if you’ve ruled out everything else above.

If repairs become too costly, purchasing a new dishwasher might be your best bet.

Do Bosch Dishwashers use Hot or Cold Water?

Bosch recommends running their dishwashers with cold water. The exception to this is if you have a better way to heat the water, such as with solar power.

Otherwise, Bosch dishwashers heat the water by themselves.

Do Whirlpool Dishwashers Heat Their Own Water?

Whirlpool dishwashers must be connected to hot water. Water should be 120 degrees as it goes into the appliance.

Whirlpool also recommends running the tap at your sink until the water is hot to increase the dishwasher’s performance.

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