What HL means
The system stopped because water in the heater reached 119°F. Don't enter the spa water.
Likely causes
- Blocked flow from closed valves or a dirty filter
Safe first checks
- Compare a digital thermometer reading with the keypad.
- With care (the heater may be very hot), make sure valves are open and the filter is clean, then turn the spa off and on to reset.
When to stop
If HL persists, Gecko's next steps are probe, heater or control replacement, which is tech work.
Checked against: Gecko Alliance Y-series and in.xe troubleshooting guide (9919-101313-D, July 2023). Codes can differ by model and year, so confirm with your owner's manual.