Display shows O3 or OZN and ozone system does not appear to run

Safety first: Turn off power before handling ozone equipment.

• Locate ozone generator: Find the small ozone unit in the equipment bay with a clear or black tube leading to the injector.
• Check tubing and check valve: Ensure the ozone tubing is connected and the check valve arrow points toward the spa water.
• Test ozone output: With power on and during a filtration cycle, feel for a slight vibration or listen for a faint buzz from the ozone unit. No sound may indicate failure.
• Replace ozone generator: Install a compatible Master Spas ozone generator if the existing unit is non-functional.
• Control output: If a new ozone unit does not run, the control pack’s ozone output may be faulty and require professional diagnosis.