Rinse temperature not reaching setpoint; Hobart dishwasher displays E3 and may not complete sanitizing cycle.

Safety first: Turn off electrical power and allow the booster heater to cool before servicing.

• Check incoming hot water: Verify that the building hot water supply to the booster is at the specified temperature and flow rate. Low supply temperature can cause E3 even if the booster is working.
• Inspect booster heater: Access the booster compartment (often under or beside the tank). Look for tripped high-limit reset buttons on the booster. Reset if tripped and monitor operation.
• Descale if needed: Heavy scale on the booster element reduces heat transfer. If you see thick lime deposits, schedule a descaling procedure using a commercial descaler following Hobart guidelines.
• Check temperature probe: Inspect the booster temperature sensor wiring and probe seating. A loose or corroded probe can misread temperature and trigger E3.
• When to call a technician: If the booster does not draw current when heating is called for, or the high-limit trips repeatedly, the element, contactor, or control board may be faulty. These are high-voltage components and should be serviced by a qualified Hobart technician.