Control panel displays E90 and spa stops heating and/or circulating water

Safety first: Unplug the spa from the mains before opening any equipment or removing filters. Never work on the spa while it is plugged in or when you are standing in water.

• 1. Check water level: Ensure the water level is between the minimum and maximum marks on the spa wall. Top up if low.
• 2. Clean or replace the filter:
  • Remove the filter housing cover inside the spa.
  • Unscrew and remove the Intex filter cartridge.
  • Rinse thoroughly with a garden hose from top to bottom to remove debris.
  • If the cartridge is deformed, very dirty, or older than 2–4 weeks of use, replace it with a compatible Intex filter cartridge.
• 3. Bleed air from the system:
  • Locate the air release valve on the pump/heater unit (usually near the filter connections).
  • With the unit OFF and unplugged, slowly open the air release until water starts to come out steadily, then close it.
• 4. Check hose connections:
  • Verify that all Intex spa hoses are firmly tightened and not kinked.
  • Straighten any kinks and re-seat the hoses if needed.
• 5. Reset the spa:
  • Plug the spa back in.
  • Press the reset/test buttons on the RCD/GFCI plug as per the manual.
  • Turn on the filtration/heating function and see if E90 clears.
• If E90 persists: The flow sensor or internal control board in the heater pump unit may be faulty. Discontinue use and contact Intex support or a qualified spa technician.