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OPERATION
Continued
Figure 34 - Locating Temperature Control
Temperature Control Settings
There are three setting knobs on the temperature control unless
your unit is specified as a boiler only with an outdoor air reset
option. If your unit is a boiler only with an outdoor air reset
option, there are additional controls for this option. They are
explained under Outdoor Air Reset Option, page 31.
The three setting knobs on the temperature control are for Set
Point, Differential, and High-Fire Offset (see Figure 35).
Maximum Set Point Determination
The maximum set point for the control is factory set. Boilers
are set to 230°F max., water heaters are set to 190°F max., and
specialty state and local codes to 200°F.
These maximum set points are established by not
cutting/cutting the OJ1 and OJ2 jumpers located on the right
side of the temperature controller (see Figure 35). The
maximum set point is determined as shown in TABLE-M.
Figure 35 - Temperature Control Setting Knobs
TABLE-L
Maximum
Setpoint
n
Note: Anytime that OJ1 is the only jumper cut, a new
overlay is required under the Set Point knob on the
temperature controller because the scale has changed to a
maximum of 190°F.
Anytime the OJ2 jumper is cut (with or without OJ1), a
new overlay is required under the Set Point knob on the
temperature controller because the scale has changed to a
maximum of 200°F.
Set Point
The Set Point knob specifies the target water temperature in
degrees, Fahrenheit. After the water temperature reaches the
set point, the temperature control shuts off the burners.
Differential
The Differential specifies the number of degrees below the set
point that the control will allow the water temperature to drop
before it brings the unit back on again.
Hydronic Heating Boilers and
Domestic Water Heaters
30
Max.
OJ1 OJ2 Set Point
Connected Connected 230°F
Cut Connected 190°F
Connected Cut 200°F
Cut Cut 160°F
TABLE - M
Maximum Set Point Determination