How to Build a Hot Water Pressure Washer?

From cleaning the grease from the cookware to washing the cars on the extreme, the hot water pressure washers are revolutionizing day by day due to their practicality.

Have you ever tried to clean the oil off a frying pan in the kitchen with chilling water? Probably not! The same is the case with the pressure washers.

How to Build a Hot Water Pressure Washer

Like cold water pressure washer breaks the dirt apart, the hot water pressure washer is meant to remove even the traces of grease out of any surface.

You know what? At a molecular level, it actually breaks the bond between oil, grease, and the surface. The poor bacteria, fungi, and algae can’t stay any more when the heated water flushes on them.

What’s the secret, by the way?

The hot water pressure washer uses pressurized air to reach the temperature of 200-degrees Fahrenheit to get the job done. It’s quite bulkier than a cold water pressure washer and offers heavy-duty cleaning.

If you’re living in a frosty climate, you certainly need this machine to get the extra cleaning power where water has more or less potential to freeze.

But wait! Have you ever wondered that getting a new hot water pressure washer will cost you three times more than a cold water pressure washer? YES, it’s way more costly and out-of-budget for some people.

Why don’t you think to build this heavy machine yourself? We’re here to aid you in this arduous operation with our complete guide.

Building a Hot Water Pressure Washer -Step-by-Step Guide


Before we get into the building process, it’s better to collect all the components you need to make a hot water pressure washer. Things you need

A Thermostat Controller:

A thermostat controller with start and stop temperature settings and a sensor is the first thing you need. Make sure it has both Celsius and Fahrenheit numberings or else things will get complicated at a later stage.

A thermostat has three displays -a start, stop, and current temperature. The sensor detects the current temperature and lets you know.

Make sure you keep the temperature between 100 and 110 degrees. The water pressure washer has seals and gaskets that may damage upon receiving excessive heat.

Electric Pond/ Aquarium Water Pump:

Choose a pump with 400 gallons water rating per hour if you want an efficient operation. It pushes the water into little ponds and aquariums.

We’ll use this pump to push water from the source to the pressure washer.

A Huge Electric Immersion Heater:

Purchase an extra-large immersion heater with a plug on one side and stainless steelhead on the other. We’re taking a 13” long structure, and if you want things to go well, choose the same.

This heater will heat the water to reach the desired temperature.

A 0.5” and a 3/4” Male-to-Male Hose Connectors

You’ll need a 0.5” hose connector to make a garden-hose connection to the water pump. Along with that, a ¾” male-to-male hose to make any other connection.

Washing Machine Hose with ¾” Female Connectors

The next thing is a hose that will connect the pressure washer and the water source. Make sure your washing machine hose has 3/4” female connectors on each side.

It can be shorter than 5-feet but not longer than that.

Optional Things

You can also have a 22-gauge steel wire that might help you to make some smooth connections. It’s fine if you don’t have this, you can get the job done with any cable or string.

Keeping a zip lock bag might help you later in the process too.

The Process:

Let’s get right into the process!

Suspend the Immersion Heater in a Bucket

Take a home depot or any 5-gallon bucket to create an entire water setup. Now, take a steel wire cable and start wounding it around one of the two legs of the heating element -the electric immersion heater.

Once you’re done making a single loop around it, suspend the heater in the middle of the bucket.

You might be wondering how can you randomly do that? Well, here’s now you have to take one end of steel wire and wound it around the bucket handle.

Repeat the step and fasten the other side of the wire on either end.

But wait! Make sure that the end of the heating element isn’t touching the bucket base. Keep it at least 2-inches above, or it may touch and melt your bucket.

Assemble the Fountain Pump

Now you have to assemble the fountain pump and make sure it has a 0.5” female opening to clasp a 0.5” male adapter. Fasten the male adapter into the pump’s hole tightly.

The other end of the male adapter will go into the hose of the washing machine having a ¾” adapter. Fasten all the connections firmly, so they don’t just open in the midway.

It’s time to take the thermostat sensor and fasten it to the pump using masking tape. In this way, the sensor won’t float in the bucket and touch the heating element.

The fountain pump has some additional weight now. It has four suction cups at the bottom and a front face from where it will suck water.

You’ll see a plus and a minus sign over the front panel. Rotate the dial clockwise to the right if you want a little water to be sucked through it. And if you want more water to go inside, turn the dial counterclockwise.

Plug in the Thermostat Controller

Once you plug your thermostat controller in power, you’ll see the start, stop, and the current temperature the sensor is reporting.

The power source will only turn on if the start temperature is less than the stop temperature. Set the range between 100 and 110 degrees Fahrenheit to power the outlet.

Lastly, make sure you’re not going above 120 degrees Fahrenheit of thermostat settings, it may damage the fountain pump seals.

Insert a ¾” Adapter into the Water Pressure Washer

The water pressure washing machine contains a hose where a garden hose or male-to-male adapter attaches. Fasten this adapter tightly into the hose of the pressure washer.

Now connect this male end to the female end of the washing machine hose.

Power up the Immersion Heater

So, the most anticipated step is right here! Plug the wire of your immersion heater into the socket of the thermostat controller.

Once the temperature reaches the desired range, the thermostat will send power to the immersion heater.

Gather all the Things in the Bucket

Build a complete setup to get things started. Along with the immersion heater, fling the water pump into the bucket to collect water from the hose downward and deliver it to the washer pressure.

If you want to take a security precaution, you can put the thermostat controller and extra wiring in the zip lock bag. Fasten the zip tie to the bucket handle to keep it in place.

The Working of the Entire Setup

After connecting the extension cord into a GFCI socket, the whole thing will come into play. Once the water starts getting hotter, you’ll notice steam coming out, and the thermostat will show the rating reaching the desired temperature.

A five-gallon bucket will take somewhere between 10 to 12 minutes to reach 110 degrees Fahrenheit. But if your air temperature and bucket size are different, time may vary too.

Once the thermostat hits the desired temperature, it will switch the immersion heater off, and you’ll notice little bubbles accumulating around the element.

The Bottom Line

Cleaning Using a Hot Water Pressure Washer

Lastly, bring your hot water pressure washer into play and check if it’s working properly.

So this is how to build a hot water pressure washer at home.

Suppose you see the hot water coming out and cleaning the stuff right away, congrats! You’ve successfully built a hot water pressure washer at home.

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