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21.3.2
FREEZE PROTECTION PUMP ON
The SMART SYSTEM control will turn on the water heater and system pump outputs whenever the inlet temperature
drops below this setting.
temperature applications (such as snow melt) can operate at temperatures around freezing, so this setting needs to
be lowered in these cases. The installer can adjust the temperature at which the pump outputs are turned on by
accessing the Freeze Protection Pump On parameter. The minimum setting is -19°C, and the maximum setting is
7.2°C. The default setting is 7.2°C.
21.3.3
FREEZE PROTECTION BURNER ON
If running the pumps does not prevent the inlet temperature from falling closer to freezing, the SMART SYSTEM
control will fire the burner at low fire. The installer can adjust the temperature at which the burner fires by adjusting
the Freeze Protection Burner On parameter. The minimum setting is -19°C, and the maximum setting is the Freeze
Protection Pump On parameter. The default setting is 2.8°C.
21.3.4
FREEZE PROTECTION BURNER DIFFERENTIAL
Once the burner has started firing due to a low inlet temperature, the inlet temperature must increase by this
amount before the burner turns back off. The installer can adjust this differential by accessing the Freeze Protection
Burner Differential parameter. The minimum setting is 0°, and the maximum is 11°C. The default setting is 2.8°C.
21.4
DHW SETTINGS
21.4.1
DHW TANK SET POINT
By installing a tank sensor, the SMART SYSTEM control can perform the tank thermostat function. The SMART
SYSTEM control automatically detects the presence of this sensor, and generates a DHW call for heat when the
tank temperature drops below the tank set point differential (Tank Set point Differential parameter), and finishes
the call for heat when the tank temperature reaches tank set point. This parameter can be changed by the installer by
accessing the DHW Tank Set point parameter. The temperature range of this parameter is from the tank minimum set
point to the tank maximum set point. The default value is 49°C. This should be set at 60°C.
The SMART SYSTEM control will only operate with r the tank sensor fitted.
21.4.2
TANK SET POINT DIFFERENTIAL
When a tank sensor is installed, the tank temperature must drop this amount below the tank set point (DHW Tank Set
point parameter) before the water heater turns back on. The installer can adjust this setting by accessing the Tank
Set point Differential parameter. The minimum setting is 0°C, and the maximum is 22°C. The default setting is 3°C.
21.4.3
DHW RECIRCULATION PUMP OFFSET (RECIRCULATION PUMP)
The SMART SYSTEM control will turn the DHW recirculation pump on when the DHW return water temperature drops
below the DHW Tank Set Point minus the DHW Recirculation Pump Offset. The range for this parameter is 0° to
30°C. The default value is 5°C.
21.4.4
DHW RECIRCULATION PUMP DIFFERENTIAL
Once the SMART SYSTEM control turns the DHW recirculation pump on, the DHW return water temperature must
increase by the DHW Recirculation Pump Differential before the control turns the DHW recirculation pump back off.
The range of this parameter is 0° to 50°C. The default value is 2°C.
This is done to prevent the water in the heat exchanger from freezing. Certain low
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