Most pressure washers operate with cold water directly from the water supply. However, there are some models that incorporate a boiler to draw hot water under pressure, and are very useful for removing stubborn dirt.
Boilerless. This type of pressure washer uses cold water and works for common cleaning tasks. The most common uses are cleaning patios, vehicles, upholstery or windows. They are perfect for all types of surfaces, as long as they are not stained with grease or oil.
With boiler. The pressure washers that incorporate a boiler are used to shoot hot water. They are more expensive but much more efficient at removing oil, grease or other hard to break down material. This reduces working time and increases the effectiveness of detergents and any type of cleaner.