Display shows EC or ECON and spa does not heat continuously to set temperature.

Safety first: No special electrical hazard from EC, but always ensure GFCI protection is present.

• 1. Check mode setting: Use the topside control to cycle through modes (Standard, Economy, Sleep). On many PDC Spas systems, pressing the Mode or Temp button toggles modes.
• 2. Select Standard mode: Choose Standard (often shown as ST or no code) to allow the spa to maintain set temperature at all times.
• 3. Monitor heating: After changing mode, allow several hours for the spa to reach the new set temperature.

If the spa still does not heat properly in Standard mode, investigate heater, sensor, or flow issues rather than mode settings.