2-5
BOILER SYSTEMS AND OPERATION
DC SERIES COMBI BOILERS DC 23-84, DC 29-106, DC 33-124, DC 33-160
F. Fan RPM at Burner Start for
Tankless DHW
Model Dependent 50-100% of High Fire
DC 23-84 = 70
DC 29-106 = 60
DC 33-124 = 50
DC 33-160 = 40 (Range = 40-75)
h Max Fan Speed Adjustment Model Dependent DC 23-84, DC 29-106 and DC 33-124 = 50
Range 40-50
DC 33-160 = 70 Range 65-75
L Indirect Tank Temperature if using
a sensor. Note: Use only IBC
12KΩ Sensor
140°F (60°C)
Fixed tank differential
of 9°F (5°C) below
the set-point, must
use an IBC 12KΩ
tank sensor
104°F - 149°F (40°C – 65°C)
L. Tankless DHW with Storage
Tank offset temperature (Boiler
operates at the Tankless Domestic
Hot Water Temperature setting
plus this offset temperature to
efciently generate DHW)
18°F (10°C) 9°F – 27°F (5°C – 15°C)
Fixed tank differential of 9°F (5°C) below the set-
point, must use an IBC 12KΩ tank sensor.
n Boiler Water Supply Temp for
heating Indirect DHW Tank
170°F (77°C) Range 140°F (60°C) to 194°F (90°C)
n. Comfort and ECO Comfort Mode:
Heat exchanger temperature
maintained while in standby
110°F (43°C) Range 0 or 104°F – 140°F (40°C – 60°C)
NOTE: If set to 0 then the temperature will be
the same as the temperature set for the Tankless
DHW in the user menu.
O. Space Heating Delay (min) 0 min Range 0 – 15 min: The Boiler will not respond to
a Space Heating call for X min.
o Space Heating Delay after
heating DHW
0 min Range 0 – 15 min: The boiler will not respond
to a call for heat after the tankless DHW call for
heat has ended for X min.
o. DHW ECO mode Learning Days 3 days Range 1 to 10: Number of days the ECO mode
uses to learn the Tankless DHW usage habits.
Rolling counter.
P Space Heating Delay after
the boiler reaches the target
temperature
5 min Range 0 – 15 min: The boiler will remain off for X
min to help reduce short cycling when the heating
load is smaller than the min ring rate.
P. Heat Exchanger Size Reference Model Dependent DC 23-84 = 24
DC 29-106 = 30
DC 33-124 = 36
DC 33-160 = 36
20 - ADVANCED INSTALLER MENU
3. Max Pump Speed (PWM)
Space Heating Only
100% For use only with a PWM style pump (Terminal
X4.5)
4 Max DHW power Model Dependent DC 23-84, DC 29-106 and DC 33-124 = 100
DC 33-160 = 75
c Min fan speed in Space Heating Model Dependent DC 23-84, DC 29-106 and DC 33-124 = 28%
DC 33-160 = 22%
c. Min Pump Speed (PWM) Space Heating Only 40%
d Min Fan power during Tankless
DHW
Model Dependent Range – 20-50%
DC 23-84, DC 29-106 and DC 33-124 = 28
DC 33-160 = 22
NOTE: The control displays codes that include upper and lower case letter and a combination with a period after the letter.
Example: C, c., c are all valid parameter codes. When adjusting settings, double check that you are in the correct parameter.