MACH® Series
Gas-Fired Boiler
Installation
Page 22
TB2) energizes providing 120 VAC power is provided
to energize a relay coil for the DHW pump. The
DHW status should be set to 1 (DHW system ON).
CAUTION!
Terminal 10 and 11 on TB2 are for pilot duty only.
they should not be connected directly to the
pump.
Outdoor Air Reset (optional):
OU TD OO R A IR vs B OI LER SETP O IN T
70
80
90
100
110
120
130
140
150
160
170
180
190
0
10
20
3 0
40
50
60
70
8 0
9 0
OUTDOO R AIR TE MP °F
B
O
IL
ER
SET
PO
IN
T
°
F
The control automatically detects the presence of the
outdoor air sensor. If an outdoor air sensor is present,
the boiler automatically defaults to outdoor air reset
for setting boiler temp. The parameters should be set
according to the following table:
Item Parameter
Value
°F
Allowable
Range °F
Maximum Setpoint
4
180
68-185
Minimum Setpoint
5
80
60-140
Outdoor Air
Minimum Temp.
6 20
4-50
Outdoor Air
Maximum Temp.
7 70
59-77
Boiler Shutoff Temp.
10
90
32-140
(32=off)
Outdoor Air Offset
12
0
0-144
Boiler Configuration
34
01
The set point of the boiler is controlled by an outdoor
temperature sensor. As the outdoor temperature falls
the setpoint of the boiler is increased. The boiler
modulates to maintain this setpoint.
The setpoint is adjusted according to the above
parameters. The boiler setpoint will be the maximum
value (180° F) when the outdoor air is at or below a
minimum temperature value (20° F). The boiler
setpoint will be at the minimum value (80° F), when
outdoor air is at or above a maximum temperature
value (70° F). The setpoint for “in between“ values of
outdoor air temperature, is linearly proportional to the
