E14 error and the spa cannot detect water level correctly; may refuse to start heating even when full.

Safety first: Disconnect power before removing hoses or opening the control box.

• Confirm water level:
  • Ensure the spa is filled to the recommended level on the liner.
• Inspect sensor tubing:
  • Locate the small pressure tube running from the plumbing or heater to the control box.
  • Check for kinks, blockages, or disconnections.
• Clear blockage:
  • Disconnect the tube at the control box and gently blow through it to clear any trapped water or debris.
  • Reconnect securely.
• Check sensor body:
  • Inspect the water level / pressure switch for cracks or corrosion.
  • If damaged, replace with a compatible Avenli sensor.
• Reset and test: After reassembly, unplug for 5 minutes, reconnect, and test. If E14 persists, the sensor or its input on the PCB may need replacement.