Display shows COOL, water temperature is significantly below setpoint and heater may be limited.

Safety first: Ensure GFCI protection is working properly when operating in cold conditions.

• Allow spa to warm: If the spa was just refilled with cold water, allow several hours for the heater to bring the temperature up.
• Verify heater icon: Check that the heater indicator is on when the spa is calling for heat. If not, verify set temperature and heating mode.
• Check cover and insulation: Make sure the Dynasty Spas cover is in good condition and properly sealed to retain heat.
• Inspect sensors: If COOL persists with warm water, a sensor may be misreading and should be checked or replaced.