F11 error; ozone or auxiliary equipment may not operate correctly.

Safety: Turn off power at the breaker before working on ozone or auxiliary circuits.

• Inspect ozone unit: Locate the Hanscraft ozone generator in the equipment bay. Check for burn marks, melted housing, or water damage.
• Check tubing and check valve: Ensure the ozone tubing is connected properly and the check valve is oriented correctly to prevent water backflow into the generator.
• Disconnect ozone temporarily: Unplug the ozone generator from the control board and restore power. If F11 clears, the ozone unit is likely defective and should be replaced.

Because ozone units operate at high voltage internally, replacement is safer than repair. Use a Hanscraft-compatible ozone generator and follow installation instructions.