High pressure fluid heater is used to reduce the viscosity of coating materials and increase operating efficiency without adding solvents. It consists of an electrical enclosure and a high-pressure fluid passage body. A cartridge heater and adjustable thermostat provide accurate fluid temperature control, and a high-temperature limiter ensures maximum operating safety. High pressure fluid heater is designed for high-flow applications, high-solids coatings and other high-viscosity materials, adjustable thermostat makes temperature setting simple and a read-out thermometer provides constant monitoring of fluid temperature. It can be wall mounted or dolly mounted using the integral mounting bracket.