Hot Water vs. Cold Water Pressure Washers

Usually, when we talk about pressure washers and their variations, we compare gas engine vs. electric motor pressure washers or residential vs. industrial models. There is one other difference that needs to be addressed as well – hot water vs. cold water pressure washers.

The reason this is not talked about as often is that cold water pressure washers are much more common than hot water ones.

In fact, many people call hot water pressure washers “steam cleaners” and believe that pressure washers are cold water only. Let’s take a difference between these two types of pressure washers and how to use them.

Difference Between Hot Water And Cold Water Pressure Washers

The main difference between these two types of pressure washers is self-explanatory – one type uses high-pressure hot water, and other uses high-pressure cold water.

The consequent differences need some explanations.

How Do Hot Water Pressure Washers Work?

Hot water pressure washer

Hot pressure washers are larger and more complex, like this Northstar model. Check price here.

These devices are designed to clean all types of dirt and debris but specialize in cleaning oil grease in particular. To do that, they use the three key elements to any effective water-based cleaning process:

  • Agitation. This describes the impact of the water hitting the dirt, oil, or grease. It’s the main function of any pressure washer, hot and cold water models alike. The higher the pressure, the more effective the water is at dislodging the dirt off the surface.
  • Soap. Depending on the task, hot and cold pressure washers alike may be able to do the job without any soap. Most harder problems will require soap, however, as it’s designed to break down all types of dirt, oily, and greasy stains at a molecular level, thus making it easier for the water to wash them away.
  • Heat. This is the one thing that distinguishes hot and cold water pressure washers. Heat alone is often enough to break down the molecular bonds in different substances, making them easier to wash away. Just think of how much easier it is to wash greasy plates with hot water than it is with cold water.

Using these three elements together, hot water pressure washers are able to clean virtually any stain you may be faced with. Doing these three things at the same time isn’t easy, however. To achieve high-pressure hot water, these pressure washers don’t just use a pump powered by a motor – they also include heating coils.

The heating coils in hot water pressure washers are typically situated after the pump. This means that the cold water coming from your garden hose is first pressurized by the pump and then goes through the heating coils.

Depending on the model, the coils themselves are usually ~200 feet long, ~half inch thick and are made out of steel pipe or tubing. They curl around multiple times to fit in the pressure washer. This allows them to heat the pressurized water up to 200 °F (~93°C) or close to its boiling point.

Gas engine hot water pressure washers heat the coils through a flame that’s created by diesel oil or natural gas/propane. Electric motor hot water pressure washers, on the other hand, heat the coils by first heating a water tank with the electric motor and then passing the coils through said tank.

Either way, once the water is both pressurized and heated, it’s jettisoned out through the pressure washer’s wand and its nozzle the same way cold water is.

Does This Mean Cold Water Pressure Washers Are Inferior?

Washing car using cold water pressure washer

Yes and no. Cold water pressure washers have a much harder time dealing with oily and greasy stains because they lack one of the three key components of any cleaning process.

That being the case, most situations where you use a pressure washer don’t require heat because the dirt there is neither oily nor greasy. Cleaning dirt and debris is just as easy with a cold water pressure washer and even stripping paint or graffiti doesn’t require heat. Creating foam with a foam cannon for washing your car also works just as well with a cold water pressure washer.

And to compensate for the lack of heat, cold water pressure washers are much more affordable (usually half the price) than hot water ones. They are much simpler in their design which means that they are much easier to maintain and less prone to developing defects.

Pros And Cons of Hot Water And Cold Water Pressure Washers

So, to sum things up, here are the pros and cons of both types of pressure washers.

Pros Of Hot Water Pressure Washers

  • They are excellent at removing any type of stain, especially oil and grease stains. If you expect to have to deal with such problems, getting a hot water pressure washer is your best bet.
  • Hot water pressure washers are just as good as cold water models at cleaning anything else too. They don’t have a downside in terms of their cleaning potential.
  • These pressure washers can also clean dirt with less pressure than cold water pressure washers because the heat compensates for the lower pressure. This means that hot water pressure washers are also better for situations where you’re afraid to damage the surface you’re cleaning with the high water pressure.
  • Because hot water pressure washers heat up the water to its boiling point, they are also called “steam cleaners”. The added benefit if that high temperature is that the steam also disinfect the surfaces of most microbes while cold water doesn’t do that.

Cons Of Hot Water Pressure Washers

  • They are much more expensive than cold water models.
  • They are much bigger, louder, more cumbersome, and difficult to handle than cold water models.
  • Their maintenance is more expensive as well.

Pros Of Cold Water Pressure Washers

  • They are excellent at removing any non-oil and non-grease related problems.
  • They are much more mobile, flexible, and easier to use and maintain.
  • They are more affordable and less costly to maintain.

Cons Of Cold Water Pressure Washers

  • They don’t deal with greasy and oily stains nearly well enough even at maximum pressure.

Which Should You Choose

The conclusion is simple – if you have oil- or grease-related problems or if you expect to face such problems in the future, get a hot water pressure washer. For virtually any other situation, cold water pressure washers are the better choice.

Learn more about pressure washers in our related articles:

Pressure Washer Uses

Gas vs. Electric Pressure Washers

How Do Pressure Washers Work?

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