Jackson dishwasher displays E6 indicating low rinse temperature; final rinse does not reach sanitizing temperature.

Safety first: Turn off power to the booster heater before opening any panels. Water inside may be extremely hot.

• Check incoming hot water: Measure the temperature of the hot water feeding the booster with a thermometer. Ensure it meets Jackson’s minimum spec (often 140°F or higher). Adjust building water heater if needed.
• Inspect booster heater: Open the booster heater access panel. Check for tripped high-limit reset buttons and reset if necessary. Look for leaks or signs of overheating.
• Test booster element: With power off, disconnect the booster heater element leads and measure resistance. An open circuit indicates a failed element that must be replaced.
• Check rinse temperature sensor: Locate the rinse line temperature probe or thermostat. Ensure it is properly clamped to the rinse line or immersed in the booster tank. Test resistance and replace if out of spec.
• Descale booster: Heavy scale on the element and tank walls reduces heat transfer. Drain the booster and descale using a manufacturer-approved descaling chemical, then flush thoroughly.

Do not rely on chemical sanitizer alone if the machine is designed for high-temperature sanitizing; restore proper rinse temperature to meet health code requirements.