Display shows OH or OHH and spa shuts down, water feels excessively hot

Safety first: Do not use the spa when an overheat condition is indicated. Turn off power at the breaker and allow the water to cool.

• 1. Remove cover and allow cooling:
  • Open or remove the spa cover to let heat escape.
  • Allow water to cool below 38–40°C (100–104°F).
• 2. Check set temperature and filtration cycles:
  • Once cooled and powered back on, verify the set temperature is reasonable (e.g., 37–38°C).
  • Review filtration and circulation schedules; reduce run times in hot climates.
• 3. Verify pump operation:
  • Ensure the circulation pump is running when the heater is on.
  • Clean filters and confirm strong water flow through heater return.
• 4. Monitor heater behavior:
  • With the cover open, observe whether the heater indicator turns off when the set temperature is reached.
  • If the heater continues to run past the set point, the heater relay on the control board may be stuck.
• 5. Replace faulty components:
  • If OH recurs despite proper settings and flow, have a technician test the temperature sensor and heater relay.
  • Replace the sensor or main control board as required.