Display shows HC or HEAT COOL CONFLICT; the unit may not start.

Safety first: Turn off power to both the heater and automation system before changing wiring or mode settings.

• Check AquaCal mode: On the control panel, verify the unit is set to the correct mode (HEAT ONLY, COOL ONLY, or AUTO HEAT/COOL) according to your installation.
• Review automation programming: In the pool controller, ensure only one demand (heat or cool) is active at a time for the AquaCal unit.
• Inspect mode wiring: If a separate mode selector or relay is used, check for stuck contacts or miswired terminals that could send conflicting signals.
• Reset systems: After correcting settings, power up the automation first, then the AquaCal unit, and verify that HC no longer appears.