When you set the differential, check that the Maximum Supply ° is higher then the boiler supply plus
half its supply temperature differential to ensure the maximum supply takes account of the
construction and safety requirements of each application (e.g., 140 °F/60 °C maximum for typical
in-slab radiant floor to avoid thermal stress).
Ensure the range between the boiler supply and maximum supply temperatures is greater than one
half of the Supply Diff'l°. Suggested Supply Diff'l° settings: High mass radiant - 20 °F/11 °C.
Example: For radiant floor - Design Supply° is 125 °F, Maximum Supply° is 140 °F, and
Supply Diff'l° is 20 °F (half of which is 10 °F) works well.
For DHW, there is only one differential setting below the target temperature. For example, if the
target temperature for the DHW is 135 °F, the differential below the target temperature will be 125
°F.
2.9 Operational settings in the Setup menu: temperature
ranges and defaults
Operational settings in the Setup Menu
Mode Setting Description
Temp.
Range
Default
DHW Tank
Setpoint°
Target temperature of DHW 95 °F-160 °F 140 °F
Boiler
Supply°
Target outlet water temperature 95 °F-185 °F 170 °F
Maximum
Supply°
Temperature limit to prevent overheating of
outlet water temperature
41 °F-190 °F 190 °F
Priority Priority of the DHW load against other loads Very Low-
Very High
Very High
Pump Post
Purge
Time (seconds) the pump will operate after
satisfying call for DHW
0-900
seconds
180 secs
Boiler Pump See Boiler Pump on page 87. On-Off On
Section: Operating concepts