1. If the ColorChlor is over a couple years old the plates may be wearing out. With proper maintenance the plates should last at least 10,000 hours of chlorine generation time.
2. If there is buildup of calcium or other material between the plates this should be removed.
If the water temperature is cold remove the ColorChlor from the water and keep in a safe place until you will use the spa again. All chlorine generators do not operate efficiently or at all at low temperatures.