Do Washing Machines Heat Water? Here’s How to Find Out

Heated water is a useful feature of washing machines. Many washing cycles rely on hot water to clean items to the best ability. 

While delicate items, such as underwear or items likely to shrink too easily, are best washed in cold water, this is rare.

Most washer owners don’t necessarily want their boiler or tankless water heater to take on the role of pre-heating water for a load of laundry. It adds unnecessary workload and could shorten their useful life.  

Do Washing Machines Heat Their Own Water?

Heating water via a boiler and keeping it hot enough to wash clothing anytime is not energy efficient.

Thankfully, this is one of the benefits of modern energy-efficient appliance design today. 

I’ve split the answer into three sections outlined below:

Heated Water – Top Loading Washing Machines

Top-loading machines aren’t usually appliances that heat water internally. Instead, they typically have two inlet valve connections, one for cold water and the other for hot water from the boiler or another source. 

This is worth factoring in if you’re in the market for a replacement washer. A ready supply of hot water may be needed, which is more expensive to provide on demand. 

Do not assume that your existing hot water setup is appropriate for what a top-loading washer appliance requires to operate and clean clothes successfully. 

Heated Water – Older Front Loading Washing Machines

Older front-loading washing machines did not always include a heating element. Instead, similar to a top loader, they often rely on two inlet water sources. 

Therefore, when acquiring a previously owned washing machine appliance, confirm if it heats water internally or is dependent on an external hot water source. 

Heated Water – Newer Front Loading Washing Machines

Newer front-loading washing machines include a heating element. 

The machine receives the cold water, then it is warmed by the heating element, until achieving the desired temperature. The exact temperature depends on the wash mode selected. 

How Does a Washing Machine Heat Water?

A heating element is fitted inside modern washers. These allow for the internal heating of water that’s received through the cold-water inlet valve at the rear of the machine. 

Most wash cycles call for approximately 40-50°C water temperature levels. Some do seek higher, closer to 90°C temperate levels, but the majority of warm water wash cycles are at a medium level. 

Heating elements are typically installed directly below the washer drum. As water is received inside the machine – by the solenoid valve being opened – it flows through the detergent drawer, and into the drum.

The water then sits at the bottom of the drum where it’s heated. Later, once the water is hot enough and there is a sufficient volume of it, the air is squeezed upward to a pressure-level water regulator.

This triggers the solenoid to close off the inlet valve water access and stop the internal cold-water flow.

Do All Washing Machines Heat Water Themselves?

Not all washing machines heat the water themselves. 

Some front-loading models include both a hot-water inlet and a cold-water inlet. However, these appliance models do not always require the use of the hot water inlet. If the model is newer, it may also have working heating elements installed. 

Most modern front loaders have a heating element present. If selecting a heated wash cycle (not a cold temperate wash for delicate items), the heating element is automatically activated. In most cases, this is true of today’s appliances to reduce their operating costs. 

Top-loading washing machines is another matter though. They are less common in households. Instead, they’re seen more in small commercial laundry rooms. These have access to substantial water boilers or multiple tankless water heaters to continually supply hot water. 

How to Check if a Washing Machine is Heating Water

The internal structure of a washing machine is substantially different when it includes a heating element versus one that does not. 

Don’t be fooled by the presence of a hot water inlet at the rear, plus a cold water one. This isn’t a powerful indicator either way. 

Here are three ways to check if your washing machine heats water:

Run a warm or hot water cycle: Put your hand up against the glass on the front loader’s door. Some are heat resistant and mask that it’s a hot water wash though. 

Check the clothes: After running a heating water wash cycle, check the damp clothes after the laundry is done. If the clothes are warm to the touch, that’s a good indicator. 

Check your product manual: Look at your printed appliance manual or download a PDF version online. There is either a section on heating water or an internal diagram that confirms the presence of a heating element. 

Bosch washing machine with its door opened

Does a Washing Machine Need Hot Water?

If the heating element has failed, what now? Does a washing machine need hot water to function properly or at all?

Most washing machines continue to operate without hot water. If your boiler is fresh out of hot water or the washer’s internal heating element is damaged, the cleanliness of your laundry is impacted. 

With that said, it’s not as bad as it once was. While detergent responds better in hot water, many detergents help you to perform a decent wash even in cold water.

It’s also possible to find a few detergents that outperform others on cold wash cycles. 

However, don’t plan to go too long without hot water for doing laundry. It’s not a good, long-term cost-saving measure. 

Troubleshooting a Washing Machine Internal Heater

Washing machines lose their internal heating system functioning for multiple reasons. It’s not always the heating element to blame!

Here are the failures that cause a loss of hot water:

  • Burnt, loose, or disconnected internal wiring (messages not getting through).
  • Sensor malfunctions (they regulate temperature management).
  • Bad control board (sending incorrect instructions).
  • Failing or failed internal heating element (water never gets heated).

One of the above results in only cold-water cycles provided by your appliance. If your washer is still within its warranty period, make a warranty call. Otherwise, the issue requires some troubleshooting. 

If you’re good at DIY, ordering parts, and fitting replacements, it’s possible to do it yourself. However, probably 80 percent of households need to call out an appliance technician when the hot water feature has failed for whatever reason. 

FAQs

Does hot water damage the washing machine?

Hot water rarely damages a washing machine. They protect the internal parts from metal wear. 

There is also a cut-off system to prevent overheated hot water from being used internally. Therefore, if one aspect of the heating system isn’t correctly controlled, the shut-off system offers a failsafe. 

Does a washing machine need both hot and cold water?

The majority of modern front-loading washing machines now heat their water. Some include a hot water inlet and a cold-water inlet to accommodate connecting a boiler or tankless-fed hot water sources. 

Hot water wash cycles perform better. Otherwise, clothes won’t get as clean. 

Does a washing machine use electricity to heat water?

Washing machines with internal heating systems use electricity to heat water. The heating element sits below the drum, receives the water, and heats it. 

Does a washing machine use hot water from the boiler?

Many top-loading washing machines and some front-loading models include hot water inlet access. This accommodates a boiler water-fed system. 

Most front-loading washer models now heat water internally using a heating element. Check the model to confirm it. 

Where is the water heated in a washing machine?

Water is heated below the washing drum, where the heating element is situated.

Water fed from the detergent drawer into the drum falls through slits in the drum to the water collector below. It is heated there before being redistributed once the thermostat confirms the H2O has reached the required temperature for the chosen wash cycle.  

To Wrap Up

It is always better to own a washing machine that heats water internally. It’s cheaper to operate and leaves plenty of hot water for showers or bath time with the kids.

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