A hot water pressure washer with an automatic burner cool-down includes a water inlet assembly, a low pressure water supply assembly, a coil outlet assembly, a control system, and other related components which are required for the functionality of the pressure washer. A shut-down timer of the control system shut down a power source so that the pressure washer can be automatically shut down through the control system when the pressure washer is not operated. Then a cool-down timer of the control system efficiently cools down a heating coil of a burner assembly. The cool-down timer activates the water inlet assembly, the low pressure water supply assembly and the coil outlet assembly through a pair of solenoid valves in order to cool down the heating coil, where the thermal energy within the heating coil is removed from a phase change of water into water vapor and convection.
