Abbreviations:
T4: Outdoor temperature(°C)
T1: Leaving water temperature (°C)
IBH: Backup electric heater
AHS: Additional heat source
Notes:
1. IBH/AHS only
2. Water flow temperature drops or rises interval
3. If IBH/AHS setting is valid, only IBH/AHS turns on; If IBH/AHS setting is
invalid, only heat pump turns on