Display shows OH or OHH, spa shuts down, pumps may run briefly then stop, water feels excessively hot near heater outlet.

Safety: Turn off power at the GFCI breaker immediately. Do not use the spa until the cause is identified. Overheating can damage components and pose a scalding risk.

• Remove spa cover and allow cooling: Leave the cover open for several hours to let the water temperature drop below 100°F (38°C).
• Check water level and filters: Verify the water level is correct and clean the Evolution Spas filter cartridge thoroughly. Restricted flow can cause localized overheating at the heater.
• Inspect circulation: With power restored, observe whether the circulation pump or low-speed on the primary pump runs continuously as designed. If there is no movement at the heater return, the pump may have failed.
• Check for closed valves: Ensure all slice/ball valves around the pump and heater are fully open.
• Reset spa: After water has cooled and flow is restored, reset power. If OH returns quickly, the high-limit sensor or heater relay may be faulty.

If the OH condition recurs, the high-limit sensor or the heater assembly should be tested and possibly replaced. This work involves live voltage and should be performed by a qualified spa technician.