The display shows COd or COLD, and the spa will not heat until the code clears.

Safety: Protect the spa from freezing. Do not drain unless winterizing fully.

• Step 1 – Allow warm-up: After filling with cold water, allow the spa to run circulation and gradually warm up. COd should clear automatically as the temperature rises.
• Step 2 – Verify sensor: If the water is not extremely cold but COd persists, test and replace the temperature sensor if necessary.
• Step 3 – Insulate: Ensure the cover is on and side panels are in place to retain heat.