How do I resolve Error 4 (ER 4) on the SpaNet SV touchpad?


Problem: Heater thermal trip activated. Heater has been active and has had insufficient water flow over the element. Low or no water flow has caused the heater temperature to exceed its maximum limits and the spa control has shut down operation to prevent any damage to the heater unit.

Cause: Low water level, airlock in pipe work, closed shut-off valves, dirty filter cartridges, filtration pump failed or operation intermittent.


  • Turn mains power OFF and wait 10-15 minutes for element to cool and thermal cut-out device to reset. Then turn power back ON

  • Check spa water level (refill if necessary)

  • Remove filters and clean as per manufacturer’s recommendations or replace cartridges if required

  • Check under spa cabinet to ensure all shut-off valves are in the OPEN position

  • Bleed airlock from pipe work by slightly loosening couplings on front of filtration pump or by removing filters and flushing water down pipe work with a hose.

How to bleed an airlock:

  1. Turn mains power OFF and wait 10-15 minutes for element to cool and thermal cut-out device to reset

  2. Find the circulation pump (as shown in picture below)

  3. Loosen the barrel union anti clockwise located on the pipe coming from the top of the circulation pump

  4. Listen for air escaping and then wait for water to start dribbling out

  5. Re-tighten the barrel union

  6. Check all T Junctions are facing upwards

  7. Turn on power to the spa

  8. Push pump A on control pad

NOTE: If the Error remains present repeat the above 8 steps to the barrel union located on the side of the circulation pump. If you still can't remedy the situation, please contact one of our customer consultant via online chat.

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