The main function of a pressure washer pump is to increase the water pressure from a garden hose or other water source and deliver that high-pressure water to a spray gun or wand. Here are some of the main functions of pressure washer pump:

1. Increase water pressure: The pump is responsible for increasing the pressure of the water that flows through the system, which is necessary to achieve effective cleaning.
2. Displace water: The pump is designed to displace water at a high rate of pressure, which is necessary for effectively cleaning dirt, grime, and other debris from surfaces.
3. Control the flow of water: The pump controls the flow of water through the pressure washer, ensuring that water is delivered at a consistent rate and pressure.
4. Generate cleaning power: The pressure generated by the pump is what gives the pressure washer its cleaning power, which is essential for removing tough stains and debris.
5. Control water temperature: Some pressure washer pumps are equipped with a heating element that can control the temperature of the water, which can help to dissolve grease and oil more effectively.

Overall, the pressure washer pump is the heart of the pressure washer system, and its main function is to generate the pressure and flow of water necessary for effective cleaning.