Arrived at location on 10/21/21 - arrived onsite to check Hatco hot water booster for dishmachine. Checked with customer and he said that periodically booster PRV would blow off hot water. Proceeded and replaced booster PRV. Allowed booster to replenish water and temperature to stabilize. Brought dishmachine into operation. Checked rinse temperature at borderline 202°. Accessed booster thermostat and turned down. Ran several racks through dishmachine for temperature to once again stabilize. Ran several more racks through dishmachine. Wash temperature @164° and rinse temperature @190°. Rinse pressure at 14psi. temperatures being maintained and PRV not blowing off. booster heater in operation.