SYX66x Commissioning Guide
V1.10.3 300117
Page 41 of 61
VT Setpoint
– This shows the current target VT Setpoint
VT Ratio
– this is the shift increase in flow temperature setpoint for each degree below 20’C outside.
Typical settings for this depend on the system being used and the available range between the min and max
permitted set points:
Underfloor Heating Systems: 1.5
Radiators in a school: 3
Radiators in a care center: 2.5
Fan Convectors: 1
Compensated Flow Low: This is a limit that sets the minimum calculated setpoint
Typical settings for this depend on the system being used and if there is a need to quickly inject more heat
without adjusting the origin and ratio:
Underfloor Heating Systems: 30
Radiators in a school: 20
Radiators in a care center: 30
Fan Convectors: 60
Compensated Flow High: This is a limit that sets the maximum calculated setpoint.
This is also the supplied heat setpoint during an optimised boost phase.
Typical settings for this depend on the system being used and if there is a need to quickly inject more heat
without adjusting the origin and ratio:
Underfloor Heating Systems: 55
Radiators in a school if uncovered: 60 if covered 82
Radiators in a care center: If uncovered: 60 (or less) if covered 82
Fan Convectors: 82
Note: Max temp setting should always be considered in relation to the radiator types/surface exposure and risk to
occupants. Any reduced flows below maximum design will ultimately reduce building heat up times and heating
output during cold periods. Warming up rates will be reduced if flow temps cannot meet the design requirement
Flow Night Setback
– The is the flow set point offset for night time operation when the Day/Night Setback heating
mode is active
VT Valve Position - The current required position of the VT Valve
