Display shows OH; spa shuts down pumps and heater to prevent overheating. Water may feel excessively hot.

Burn hazard: Water may be hotter than 40°C (104°F). Turn off power at the breaker and open the cover to allow cooling.

• Do not enter the spa: Wait until the water temperature drops to a safe level before using the spa.
• Clean filter and check flow: After cooling, clean or replace the Hanscraft filter cartridge and verify strong flow from circulation and jet returns.
• Monitor heater indicator: With power restored, watch the control panel. If the heater icon remains on even when the set temperature is reached, the heater relay may be stuck and requires control board service.
• Check sensor placement: Ensure the temperature sensor is properly seated in the heater well and not touching the metal directly in a way that could cause false high readings.

Repeated OH errors require professional diagnosis of the heater circuit and sensors to prevent damage or scalding risk.