Display shows OH or OHH and spa shuts down; water may feel excessively hot near heater return.

Safety: Do not use the spa when an OH/OHH error is present. Turn off power at the breaker and allow water to cool below 38°C (100°F) before troubleshooting.

• Remove cover and cool water: Take off the RivieraPool spa cover to allow heat to dissipate. Let the spa sit powered OFF until water temperature drops.
• Check circulation: Once cooled, restore power and verify that the circulation pump is running and that there is strong flow from the heater return jets. Clean or replace the filter if flow is weak.
• Inspect temperature sensor: Locate the RivieraPool temperature sensor (probe inserted into the heater tube or spa shell). Check for kinks, damage, or loose connections at the control board. A sensor reading too high can falsely trigger OH.
• Test heater operation: With the spa calling for heat, feel the heater tube. If it continues to heat even when the set temperature is reached or when the spa is in an error state, the heater relay on the RivieraPool control board may be stuck closed.
• Corrective action: Replace a faulty temperature sensor first, as it is simpler and less expensive. If overheating persists, the RivieraPool control pack (circuit board with heater relay) may need replacement by a professional.