E12 error code appears; spa may shut down or lock out heating and bubble functions.

Safety first: Unplug the spa before any inspection. Internal PCB access should only be done by qualified personnel.

• Extended power reset: Disconnect power for at least 30 minutes to fully discharge capacitors and reset internal logic.
• Check for surge damage: Inspect the power cord and GFCI for burn marks or melted plastic that might indicate a surge event.
• Stable power source: Plug the spa into a known-good outlet on a dedicated circuit. Avoid circuits that frequently trip or dim lights.
• Retest functions: After reset, run filtration only, then gradually enable heating and bubbles to see if E12 reappears.
• Ongoing E12: If the error returns, the main PCB or internal communication bus is likely damaged. Replacement of the pump/heater unit or PCB is typically required.

Warning: Do not attempt to reprogram or modify spa firmware; unauthorized changes can disable safety features.