Operating instructions

56
Outdoor Reset Control
In accordance with Section 325 (f) (3) of the
Energy Policy and Conservation Act, this
boiler is equipped with a feature that saves
energy by reducing the boiler water tem-
perature as the heating load decreases. This
feature is equipped with an override which
is provided primarily to permit the use of
an external energy management system
that serves the same function.
THIS OVERRIDE MUST NOT BE USED
UNLESS AT LEAST ONE OF THE FOL-
LOWING CONDITIONS IS TRUE.
• An external energy management sys-
tem is installed that reduces the boiler
water temperature as the heating load
decreases.
• This boiler is not used for any space
heating
• This boiler is part of a modular or mul-
tiple boiler system having a total input
of 300,000 BTU/hr or greater.
• This boiler is equipped with a tankless
coil.
Adjusting Outdoor Reset Curve
The appliance CH set point along with
Parameters 5, 6 & 7 define the settings of the
outdoor reset curve. See Graph 1 and Table 7,
page 57 for an example of modifying the out-
door reset curve.
CH Maximum Boiler Operating
Temperature
If an outdoor temperature sensor is not con-
nected to the appliance, the appliance setpoint
for a heating call will be set to the CH
Maximum Boiler Operating Temperature
Setpoint. If an outdoor temperature sensor is
connected, the CH Maximum Boiler
Operating Temperature Setpoint becomes the
appliance setpoint on the CH Reset Curve
Coldest Day.
CH Minimum Boiler Operating
Temperature Setpoint
(Parameter 5)
This parameter is not applicable if an outdoor
sensor is not connected to the appliance. When
an outdoor temperature sensor is connected, the
CH Minimum Boiler Operating Temperature
Setpoint becomes the appliance setpoint on the
CH Reset Curve Warmest Day.
CH Reset Curve Coldest Day
(Parameter 6)
This parameter is not applicable if an outdoor
sensor is not connected to the appliance. When
an outdoor temperature sensor is connected, the
CH Reset Curve Coldest Day is the coldest
design temperature of the heating system.
CH Reset Curve Warmest Day
(Parameter 7)
This parameter is not applicable if an outdoor
sensor is not connected to the appliance. When
an outdoor temperature sensor is connected, the
CH Reset Curve Warmest Day is the warmest
design temperature of the heating system.
NOTICE
Factory Setting
Minimum
Setting
Maximum
Setting
186ºF
[86ºC]
86ºF
[30ºC]
194ºF
[90ºC]
Factory Setting
Minimum
Setting
Maximum
Setting
64ºF
[18ºC]
59ºF
[16ºC]
77ºF
[26ºC]
Factory Setting
Minimum
Setting
Maximum
Setting
00ºF
[- 18ºC]
-22ºF
[-30ºC]
50ºF
[10ºC]
Factory Setting
Minimum
Setting
Maximum
Setting
86ºF
[30ºC]
59ºF
[16ºC]
140ºF
[60ºC]