Atlantic water heater displays E6 and heating is disabled.

Safety: Turn off power and verify isolation before touching the electronics.

• Inspect the control board compartment for signs of water ingress or condensation. Dry the area thoroughly and correct any leaks from the tank flange or piping.
• Check for visible burn marks, swollen capacitors, or cracked components on the Atlantic control board.
• Ensure all connectors are firmly seated and that the ground connection is secure.
• If E6 persists after power cycling and there is no obvious wiring issue, the control board is considered defective.
• Order and install the exact replacement Atlantic electronic control module specified for your model. Transfer any configuration jumpers as per the service instructions.
• After replacement, reprogram temperature and operating modes as needed and verify normal operation.