Ozone indicator is off and no ozone bubbles are visible when the circulation pump runs.

Safety first: Turn off power before handling the ozonator or tubing.

• Verify settings: Check the spa’s control menu to ensure ozone is enabled (if user-configurable on your model).
• Inspect tubing: Follow the ozone tubing from the ozonator to the injector. Ensure it is connected, not kinked, and that the check valve is oriented correctly.
• Check for bubbles: With power on and circulation running, look for fine bubbles at the ozone injection point. No bubbles may indicate a failed ozonator or blocked injector.
• Replace ozonator: If the unit is older than its rated life (often 3–5 years) or shows no output, replace it with a Caldera-compatible ozone generator.