A hot water pressure washer is a cold machine with a burner in it, lifting the water to roughly 180 to 200 degrees on its way to the gun. That heat is what dissolves grease, oil and food fats, and on those soils more pressure alone only moves the mess somewhere else. Day rates commonly run $150 to $300, against $60 to $110 for a cold water unit of similar output.
When the heat is worth the extra rate
Hire hot for anything oily: workshop floors, engine bays, kitchen extraction, fryer areas, machinery going back to a yard, and grease tracked across concrete. Hire cold for dirt, moss, algae and general grime, where the temperature adds nothing. Paying triple the day rate to wash a fence is the mistake this counter sees every spring.
Flow matters as much as pressure
Pressure breaks the bond and flow carries the soil away, so a machine at 3,000 psi and 4 gallons a minute clears ground far faster than one at 4,000 psi and 2. Rental hot units typically sit around 3,000 to 4,000 psi with 3 to 5 gallons a minute. Ask for both numbers rather than the pressure alone.
What it needs on site
A hot unit wants a water supply that keeps up with its flow, which is more than a garden tap manages on the larger machines, so a tank and a float feed is common. The burner runs on diesel or kerosene, usually supplied by you and billed if the yard fills it. Electric start units also need a power source.
Never run the burner indoors
The burner produces combustion exhaust, so a hot water machine belongs outside or in a space with real ventilation, with the unit outdoors and only the hose run inside. Every yard says this at the counter and it is the rule people ignore in cold weather. Carbon monoxide gives no warning before it puts somebody on the floor.
Questions people ask about hot water pressure washer rental
Is hot water pressure washing actually better?
On greasy and oily soils, decisively, because the heat softens what pressure alone just spreads. On mud, moss and general dirt a cold machine does the same job for a third of the rate. Match the machine to the soil rather than assuming hotter is always better.
What psi do I need?
Around 3,000 psi handles concrete, plant and workshop floors. Softer surfaces such as timber and painted siding want far less and a wider fan tip. Look at gallons per minute too, since flow is what actually carries the loosened dirt off the surface.
Does the yard supply the burner fuel?
Usually the machine leaves with a full tank of diesel or kerosene and you return it full, or it is refilled and billed at the counter rate. Confirm which fuel it takes before you fill it, because putting the wrong one in a burner is an expensive way to end a hire.
Can I use one inside a building?
Only if the machine itself stays outside and just the hose comes in. The burner exhausts combustion gases including carbon monoxide, so an enclosed space with the unit running in it is genuinely dangerous. For indoor work an electric cold water machine is the safe answer.