Control panel displays E91 and spa will not run filtration or heating

Safety first: Disconnect power at the outlet and ensure the RCD/GFCI is off before touching any components.

• 1. Inspect water level and suction:
  • Confirm water level is correct.
  • Check that the suction grid and outlet fittings inside the spa are not blocked by leaves, hair, or debris.
• 2. Service the filter:
  • Remove the Intex filter cartridge.
  • Clean thoroughly with a hose or replace with a new Intex cartridge if it looks worn or clogged.
• 3. Check hoses and valves:
  • Ensure all hoses between the spa and heater pump unit are fully open and not twisted.
  • Verify that any shutoff caps or plugs used for winterizing are removed.
• 4. Bleed trapped air:
  • Open the air release valve on the pump unit until water flows steadily, then close.
• 5. Restart the system:
  • Plug the spa back in and reset the RCD/GFCI.
  • Turn on filtration and check if E91 clears.
• If E91 remains: The circulation pump or internal flow path in the heater pump unit may be restricted or failing. Professional diagnosis or replacement of the heater pump unit is recommended.