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3. O
PERATING
O
PTIONS
The furnace is shipped from the factory in a “Standard Heating Mode” (all switches are in the Down position). When the thermostat calls for heat, the automatic
controls will be activated and the furnace turned “ON”.
The blower will run at low speed as the furnace heats up and will automatically switch to the pre-programmed heating speed when additional elements are
activated by the time delay relays.
The timing of this blower speed change will depend on the size of the furnace (10 kW and 13.5 kW models do not change speed), and whether
C
OLD
or
M
ILD
is selected on the
SEASON SELECT
switch.
You may, however, change from the Standard Heating Mode by using the controls built into your furnace.
O
N
O
FF
RECIRCULATION MODE
M
ILD
C
OLD
(NOT INCLUDED IN MODELS
21B10M AND 83B13)
SEASON SELECT
O
N
–
Some homeowners prefer the blower to run at low speed to more
evenly distribute air in the house. In this position, the blower will
run continuously on low and automatically change to the necessary
heating speed when heating elements are turned on by the
thermostat.
O
FF
–
The blower motor will operate in the standard heating mode, controlled
by the thermostat.
M
ILD
–
During spring and fall, you may not require full heating capacity to
maintain a comfortable temperature. In this position, approximately
half of the elements are “off-line” and will not be energized when
the thermostat calls for heat.
C
OLD
–
All elements are “on-line” and controlled by the thermostat.
NOTE: If outdoor or two-stage thermostat is used, switch MUST be in
M
ILD
position at all times.
4. B
REAKERS
B Series furnaces are equipped with breakers, located on the front panel
of the unit. These devices protect the heating elements from overcurrent.
If this situation occurs, the breakers will open to cut the power from the
heating elements only.
NOTE: The number of breakers varies according to the furnace
model; 21B10M model has no breakers, 21B15M, 21B18M,
21B20M and 83B13 models have 2 breakers and 21B25M,
21B27MS, 83B24 and 83B27 models have 3 breakers. Refer to
Section 8 Wiring Diagrams.
WARNING
Breakers do not cut power to entire furnace, only to the heating elements. Do not use the breakers to turn off the furnace.
The power to the whole unit can only be cut from the main electrical panel.
FD0003
B
REAKERS
