User Manual

Slant Fin Corp. │Controller and Display CHS Series
14
2.4.2 DHW Config
Figure 2-13 Domestic Hot Water Configuration Screen
DHW Config – menu screen, accessed by selecting
“DHW Config” from the “Advanced Setup” screen, lists
the configuration parameters specific to boiler operation
for a DHW demand. Use the up and down (▲▼)
buttons to navigate the menu options; when the desired
option is highlighted select by pressing the “OK” button.
Demand switch - DHW demand can be initiated by a
contact closure, “DHW switch”, or by a tank
temperature sensor, “DHW Sensor with On/Off Temp”.
Mod sensor – The control can be set to use the “Outlet”
or “Inlet” sensor for regulation of burner modulation.
When “Demand switch” is set to
“DHW Sensor with On/Off
Temp”, demand is determined by
the Demand ON and OFF temp settings.
Table 2-9 DHW-Domestic Hot Water Configuration Parameters
Parameter
Description
Factory Settings
Demand
switch *†
Select which sensor is the DHW demand source:
 DHW switch
 DHW Sensor with On/Off Temp
(If “DHW Sensor with On/Off Temp is selected, a tank sensor must be used to
generate a demand.)
DHW switch
Mod
sensor *
Select the DHW modulation sensor:
 Outlet
 Inlet
Outlet
DHW
setpoint
Setpoint for DHW modulation. If “Mod sensor” is set to “DHW” or “Inlet”, reduce
setting accordingly. Range 60°F to 190°F
180°F
Off
hysteresis *
Value added to “DHW setpoint” to determine water temperature at which the burner
will shut off e.g. if “DHW setpoint” is 180°F, and “Off hysteresis” is 10°F, the
burner will be shut off at 190°F. Range 5°F to 70°F
10°F
On
hysteresis *
Value subtracted from “DHW setpoint” to determine water temperature at which the
burner will fire e.g. if “DHW setpoint” is 180°F, and “On hysteresis” is 10°F, burner
ignition occurs at 170°F. Range 2°F to 40°F
10°F
Priority
time *
Time period during which a DHW demand has priority. If override time has elapsed,
the boiler and CH pump (Pump C) will service a CH demand regardless of DHW
demand. Value=0 inhibits DHW priority. Range 0 to 18 hours.
2 hour
Demand
ON temp *
DHW demand is switched ON when DHW tank temperature is < this setting.
Applied when “Demand switch” is set to “DHW Sensor with on/off temperatures”.
Range 60°F to 165°F.
135
o
F
Demand
OFF temp *
DHW demand is switched OFF when DHW tank temperature is ≥ this setting.
Applied when “Demand switch” is set to “DHW Sensor with on/off temperatures”.
Range 65°F to 170°F.
140
o
F
* = Password protected
† = If “Demand switch” is set to “DHW Sensor with On/Off Temp”, demand is determined by the Demand ON and OFF temp settings.
DHW tank sensor MUST be used in conjunction with a DHW temperature safety shutoff
switch. Failure to provide such a switch may result in property damage, serious injury to
occupants, or possibly death.
Demand switch
Mod sensor
DHW setpoint
Off hystersis
On hysteresis
Demand ON temp
Demand OFF temp
DHW switch
Outlet
180
o
F
10
o
F
10
o
F
135
o
F
140
o
F
DHW Config