Jackson dishwasher shows E9 and shuts down; control detects an over-temperature condition in tank or booster.

Safety first: Turn off power and allow the machine to cool completely. Do not reset high-limits repeatedly without finding the cause.

• Verify water level: Ensure the tank and booster are properly filled. Low water can cause rapid overheating of elements.
• Inspect and reset high-limit thermostats: Locate manual-reset high-limit thermostats on the tank and booster. Press the reset buttons. If they trip again quickly, investigate further before reuse.
• Check temperature control devices: Test the operating thermostat or temperature controller for proper cut-in and cut-out temperatures. Replace if it fails to open the heater circuit at the setpoint.
• Inspect heater contactor/relay: A welded contactor can keep heaters energized continuously. Inspect for welded contacts and replace the contactor or solid-state relay if defective.
• Descale sensing surfaces: Heavy scale on probes or thermostat bulbs can cause inaccurate readings. Clean with approved descaler.

Persistent over-temperature faults can damage tanks, gaskets, and electrical components; involve a Jackson-authorized technician if the root cause is unclear.