Fedders operation and, Installating And Operation Manual

THERMOSTAT

COOLING 

CONTACTOR

FAN 

RELAY

HEATING RELAY

24V

115V

R

G

Y

W

Y

G

W

ISOLATION RELAY

THERMOSTAT LOCATION 

The thermostat should be located approximately 5 feet above
the floor, on an inside wall where there is good natural air
circulation, and where the thermostat will be exposed to
average room temperatures. Avoid locations where the
thermostat will be exposed to cold drafts, heat from nearby
lamps or appliances, exposure to sunlight, heat from inside
wall stacks, etc. 

THERMOSTAT HEAT ANTICIPATOR SETTING: 0.45 AMP (White-

accessories such as electronic air cleaners and power
humidifiers. 

ELECTRICAL WIRING AND COMPONENTS MUST BE PROTECTED
FROM MOISTURE, INCLUDING WATER AND CONDENSATE. 

DEHUMIDIFICATION OPTION

The controller has a dehumidification option. When high
humidity is sensed (requires a 24 volt Humidistat that opens on
high humidity) the air flow is reduced to increase condensing.
To activate, the jumper  labeled “DEHUM” must be moved to
the “yes” position. 

AIRFLOW

WARNING

Make adjustments to the controller with the electrical
power off.

WARNING

ALL CONTROLLER JUMPER CHANGES MUST BE MADE
WITH POWER DISCONNECTED TO THE FURNACE.

The ECM TM blower is preprogrammed from the factory to
hold constant flow. (Replacement motors must have the
correct part number and can only be ordered from the furnace

size A/C tonnage as well as an adjustment in flow. Changing
the Heating Tap changes the Temperature Rise in about 5 F

If the Adjust Tap is used for cooling then the heating speed
should be adjusted to counter the effects of the adjustment
tap. Rule of thumb: The Heating Tap will be the same as the

START UP PROCEDURES

This furnace is equipped with a hot surface ignition (HSI)
device. Each time that the room thermostat calls for heat,
the HSI lights the main burners directly. See the lighting
instructions on the furnace.

To Start The Furnace:

1.  Remove the burner compartment access door.

2.  Shut off the electrical power to the furnace and set the

room thermostat to its lowest setting.

3.  Ensure that the ignition system control switch on the

gas valve is in the “ON” position.

4.  Replace the burner compartment access door.

5.  Restore electrical power to the furnace.

6.  Set the room thermostat to a point above room

temperature to light the furnace.

7.  After the burners are lit, set the room thermostat to the

desired temperature.

To Shut Down The Furnace:

1.  Set the room thermostat to its lowest setting.

2.  Remove the burner compartment access door.

3.  The ignition system control switch on the gas valve may

be switched to the “OFF” position.

4.  The furnace appliance shutoff valve may be closed if

desired.

SHOULD OVER HEATING OCCUR, OR THE GAS BURNERS
FAIL TO SHUT OFF, CLOSE THE MANUAL GAS VALVE FOR

POWER TO THE FURNACE. FAILURE TO DO SO CAN
CAUSE AN EXPLOSION OR FIRE RESULTING IN PROPERTY
DAMAGE, PERSONAL INJURY OR LOSS OF LIFE.

WARNING

i

THE FURNACE BEFORE SHUTTING OFF THE ELECTRICAL

Sequence of Operation

1.   Room temperature drops causing the room thermostat

heating W1 contacts to close. 

2.   The inducer blower is energized at high speed and the

control waits for the low pressure switch contacts to
close.

3.  Once the low pressure switch contacts close, a 15-

second pre-purge is initiated.  Then the inducer

powered.

heats up; 10 seconds on a first try, maximum 14 seconds
on a subsequent retry.

and cooling speed. Heating Tap A is factory set for heating speed.

increments. The Taps are in a row of jumper labeled “COOL”,
“HEAT” and  “ADJUST”. 

“ADJUST” Tap.

33

Rodgers) See page 39 for information on connecting optional

Table on page 36 shows the recommended taps for heating

manufacturer.) Changing the Taps allow adjustment for various

changes to low speed and the 120VAC ignitor is

4.  After the prepurge period, the hot surface ignitor