1 Service (continued)
Freeze protection pump on
In order to prevent the water in the heater from freezing, the SMART SYSTEM control turns on the boiler pump whenever the inlet temperature goes below the minimum temperature. The range of this parameter is 32°F (0°C) to 104°F (40°C). The default value is 45°F (7°C).
Freeze protection burner on
If the inlet temperature continues to drop after strating the pump (see Freeze Protection Pump On), and the inlet temperature goes below a second minimum temperature, the first stage will fire. The temperature range of this parameter is 32°F (0°C) to 104°F (40°C. The default value is 37°F (3°C).
Freeze protection differential
Once the pump has turned on, this parameter determines how much the inlet temperature must rise before the pump turns off. Similarly, once Stage 1 has turned on, this parameter also determines how much the inlet temperature must rise before Stage 1 turns back off. The temperature range of this parameter is 0° to 72°F (40°C). The default temperature is 5°F (3°C).
DHW/SH switching time (boiler only)
The time that the SMART SYSTEM control services a DHW demand before returning to the SH demand is set by this parameter. The range of this parameter is 0 to 240 minutes. Setting this parameter to 0 disables the switching function. The default value of this parameter is 30 minutes.
DHW Tank offset (water heater only)
The tank offset is the number of degrees the DHW tank temperature must go above the tank setpoint before the water heater will turn off. The temperature range of this parameter is 0° to 10°F (5°C). The default value is 4°F (2°C).
DHW Tank differential
The tank differential is the number of degrees the DHW tank temperature must go below the tank setpoint before the heater or boiler will start to heat the DHW tank. The temperature range of this parameter is 0° to 40°F (22°C). The default value is 6°F (3°C).
DHW settings
DHW tank setpoint
When a temperature sensor is installed in the DHW tank, the DHW tank setpoint sets the target temperature of the water in the tank. The temperature range of this parameter is 60°F (15°C) to 190°F (88°C). The default value is 120°F (49°C).
DHW boiler setpoint (boiler only)
When an indirect DHW call for heat becomes active, the control will use the DHW boiler setpoint to determine the firing rate of the unit based on the actual outlet water temperature. The temperature range of this parameter is 32°F (0°C) to 261°F (127°C). The default value is 180°F (82°C).
SH/DHW switching time (boiler only)
When a SH call for heat and a DHW call for heat are present at the same time, the SMART SYSTEM control can switch back and forth between the two calls. This parameter determines the maximum length of time the boiler will service the SH call before switching to the DHW call. The range of this parameter is 0 to 240 minutes. Setting this parameter to 0 disables the switching function. The control will service the DHW demand until it ends, then return to the SH demand (if active). The default value of this parameter is 30 minutes.
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