Display shows COOL and heating is temporarily suspended

Safety first: Ensure the spa is filled and all jets are submerged before running pumps.

Steps to address COOL:

• Allow time to heat: After a refill or power restoration, the spa may take many hours to reach set temperature. COOL will clear as the water warms.
• Verify heater operation: Confirm that the heater indicator is on and that the circulation pump is running. Check for warm water at the heater return after 30–60 minutes.
• Check sensor accuracy: Compare displayed temperature to a thermometer. If readings differ significantly, inspect and possibly replace the temperature sensor.

When to call a technician: If COOL persists and the water does not warm despite the heater being commanded on, the heater or control pack may require professional diagnosis.