Hot Tub H2O Message

On some Sapphire Spas models the spa may experience an air lock in the heater tube after a routine drain and refill.  In these cases the touchpad display may display “H2O” or “Prime Failure” and the spa will switch off accompanied by a beeping sound.  The heater has a fail-safe mechanism so that, if there is insufficient water in the heater tube, it prompts this warning to avoid damage to the heater element.  The air lock can easily be removed by following these simple steps.

1. Turn off the mains supply to the spa.

2. Ensure that the spa is filled to the correct level.


3. Open the key lock door of the spa and locate the controller which will be a plastic box with a large plastic tube passing through the bottom of it.

4. The black plastic unions at either side to the tube are only had tight.  Carefully loosen one of these unions and prise apart the connection until you can hear air escaping.  Keep the connection loose until all of the air has escaped and it is just water that is escaping.  At this point tighten up the union by hand.
5. Turn on the mains supply to the spa and turn the main pump to its high speed mode.  After a minute, provided the spa does not show the error message again, put the controller into its automatic mode and wait for the heater light to come on.  If the heater light comes on and the error message does not reappear then the air lock has been successfully removed.  Refit the key lock door.


6. If the error message reappears, reset the controller using the buttons on the touchpad as per the owners’ manual.  If it still persists, repeat the bleed procedure using the other side of the controller.


7. If the error persists, there may be a fault with the controller, so please call us on 01869 327698.