Will a Dishwasher Work With No Hot Water (Let’s Find Out)

will a dishwasher work with no hot water
Will a Dishwasher Work With No Hot Water (Let's Find Out) 2

Finding your dishwasher has no hot water is frustrating. You may be asking – will a dishwasher work with no hot water?

Without enough hot water, dishwashers cannot clean and sanitize dishes at the necessary temperature to achieve optimum results. This means that dishes may not come out as clean as intended, and bacteria may remain on them after the cycle is complete.

You can run a dishwasher without hot water, but you won’t get the same result in terms of cleanliness for your dirty dishes. Using cold water would not ruin your dishwasher either. 

However, having a hot water supply helps sanitize and get your dishes cleaner, as a hotter temperature equals killing germs and bacteria better. Some modern dishwashers will offer a heat boost option to heat water, but most models do not.

Check for an error code if you have a newer dishwasher and no hot water. These codes can point you to why your dishwasher doesn’t have hot water.

Dishwasher manufacturer installation calls for a supply line connected to the hot water supply. However, I have seen dishwashers connected to the cold water supply in some rare instances. Most of these had an under sink water heater (point of service) installed.

Given the information above, let us understand more about the temperature used for a dishwasher and if there may be any issues with using cold water. Keep reading to find out more! 

Will a Dishwasher Work With No Hot Water?

You can use a dishwasher with no hot water, as mentioned above. You can wash dishes with hot or cold water, but cold water won’t clean dishes and silverware properly when the wash cycle completes.

What we mean by this is that warm water is highly effective at sanitizing and killing off microorganisms and bacteria, according to the USDA (US Department of Agriculture). In that case, it is best to run the dishwasher settings hot. 

On top of that, many dishwashers have a water heating element at the bottom for drying, so keeping the internal thermostat at your desired temperature is relatively hard.

Do Dishwashers Need Hot Water Supply?

Some homeowners may wish to decrease hot water consumption while running the dishwasher to save money. Although it sounds like an excellent idea, your dishwater won’t clean as well in washing cycles. The internal thermostat inside some models boosts the temperature of the water but isn’t designed to heat cold water fully. Hot water helps break down food particles and keeps residue from occurring.

Given that information, a dishwasher needs to run on hot water. It will clean much better with the hottest water possible, so we recommend those settings if that is an option.

In other cases, there may be a dishwasher model with a bad heating element. If this is the case, then the quality of how clean your dishes become will not be the best the longer you keep that model.

For example, if you have a modern dishwasher, it might have electric heating elements that warm the unit’s interior. However, if you acquired an average dishwasher, you might need to manually put hot water in yourself. 

The heating element in the bottom of the dishwasher is for drying dishes, not the heating process of cold tap water.

How Hot Does a Dishwasher Get?

According to GE products, the ideal dishwasher temperature is between 120 to 150 degrees Fahrenheit. If installing the dishwasher yourself, please connect the dishwasher to the hot water line instead of the cold. 

In commercial kitchens, when washing dishes, the water needs to be 165 degrees Fahrenheit to sanitize dishes. Most incoming hot water in residential homes is between 105 and 115 degrees. The heat boost option for the cleaning cycle raises the water temperature for washing dishes, but it won’t be effective on straight cold water.

If you suspect your water temperature is not hot enough, use a thermometer to check and see how hot it is. You do this by taking the following steps:

  • Turn the faucet on nearest to where the dishwasher is.
  • Get a cup or glass, then put the thermostat inside.
  • Afterward, allow the water to run inside the cup for a couple of minutes.

If the hot water heater is relatively far away or you have an older model, make sure to run the water in the kitchen sink so it can get hot before running the machine itself. 

Do Dishwashers Need a Direct Hot Water Input?

A washing machine uses both a cold and hot water supply for washing clothes, so you might wonder if dishwashers do the same. A dishwasher directly connects to the hot water line and only needs hot water for cleaning. Dishwashers do not connect to the cold water line. 

Will My Dishwasher Work if the Water Heater is Broken?

Suppose your water heater just broke, and you need it fixed. In that case, it might be wise to rethink that strategy because a dishwasher will not work if the water heater breaks or turns off. 

Realistically, you can heat your own water on the stove and place it in the dishwasher if you genuinely wish, but this would be more daunting in the long run.

How Does a Dishwasher Heat Water?

A dishwasher heats water by using an internal heating element. The water is first drawn into the dishwasher and passed through a filter before entering the heating chamber, heated up to optimal temperatures for cleaning dishes. The heated water is then sprayed onto the dishes, providing a hot and effective way to clean them.

What are Some Signs a Dishwasher isn’t Using Hot Water?

If you suspect your dishwasher is not using hot water, there are a few physical signs to look for. As mentioned above, you could easily use a thermometer to help identify this issue. If your dishes don’t come out as clean, there may be a lack of hot water.

However, some people do not wish to take this approach, and you might see other noticeable things beforehand. 

1. You Have Dish Detergent Residue

Heat removes soapy residue unless you have a specific brand that constantly has this issue. However, dish detergent is much heavier than regular soap, which will quickly cut through grease and food.

However, intense water pressure and hot water take that residue away. The soap residue will remain after the final rinse and drying cycle if the water is not hot enough. 

Something else to keep in mind is that unheated water will keep the dish soap chemicals on your dishware, making it get into your body by eating and drinking it.

2. Food Remains on the Dishes

The last way to check and see if your water is not running at the desired temperature is to catch food particles on the dishes. One prominent sign is to check your silverware. 

Suppose you took your favorite alfredo meal in your room to eat and watch your favorite show but forget about the dish for two days. 

In that case, the silverware will have caked alfredo sauce left on it. However, after running the dishwasher cycle, you found that it is not coming off, even after hand washing it in the sink for two whole minutes.

If this is the case, your dishwasher most likely is not running at a high enough temperature.

Conclusion

A dishwasher can and will work with no hot water to quickly go over everything. On the other hand, is it a wise decision to do so? Not really, but it is still doable. Dishwashers are ineffective at heating water to optimal washing cycle needs with cold tap water. At best, you’d end up with lukewarm water.

Remember that the dishwasher water temperature should be between 120 to 150 degrees Fahrenheit, so if it does not reach those temperatures, make sure to check your water heater or have a professional look at it. 

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Hubert Miles

I've been conducting home inspections for 17 years. I'm a licensed Home Inspector, Certified Master Inspector (CMI), and FHA 203k Consultant. I started HomeInspectionInsider.com to help people better understand the home inspection process and answer questions about homeownership and home maintenance.
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