Heating Curve Dial
Before adjusting the dial settings, read through the
sequence of operation to ensure that you understand
how the control operates.
During outdoor reset operation, the
Heating Curve setting determines
the number of degrees the supply
water temperature is raised for each
one degree drop in outdoor
temperature. The Heating Curve
dial position can be calculated from
the following formula.
Heating Curve =
Design supply temperature – occupied temperature
Occupied temperature – design outdoor temperature
Example: A system is designed to supply 120°F
(49°C) water when the outdoor temperature is 10°F
(-12°C). The Occupied temperature is 70°F (21°C).
Heating Curve =
120 - 70°F (49 - 21°C)
70 - 10°F (21 – (-12°C))
50°F (28°C)
60°F (33°C)
Page 14
=
= 0.8
Figure 8B -
Heating Curve Dial
Dip switch settings
POSITION
SWITCH
ON
OFF
DEFAULT
A
Permanent
External
ON position
Demand
Demand
Permanent Demand
Max system
Max system
ON position
B
supply set
supply feature
supply set at
at 140
o
F
is off
140
o
F
Boiler return
Boiler return
ON position
C
minimum set
minimum feature
minimum set at
at 135
o
F
is off
135
o
F
D
Heating curve
Heating Curve 5
o
F
On position
No shift
Parallel shift
No shift
