Page 9 of 18
507388-01
Issue 1504
Blower
The unit contains a direct-drive, multispeed blower. The proper
speeds have been preset at the factory for heating and cooling.
Refer to the wiring diagram for recommended
heating/cooling speeds for specific models. Direct-drive blower
motors are permanently lubricated and do not require oiling.
Limit Control
A fixed temperature limit control is provided which will shut
off the gas to the main burners if the unit is overheated for any
reason. The control must not be adjusted or relocated.
High Altitude Adjustments (U.S. Installations)
Ratings shown on the rating plate are for elevations up to 2000
feet. For elevations above 2000 feet, ratings should be reduced at
a rate of 4% for each 1000’ above sea level. Refer to the National
Fuel Gas Code Z223.1 (latest edition) for further explanation.
High Altitude Adjustments (Canadian Installations)
High altitude conversions may be made by the manufacturer’s
authorized representative, in accordance with the requirement
of the manufacturer, provincial, or territorial authorities having
jurisdiction, and in accordance with the requirements of CAN/CGA
B149.1 or B149.2 Installation Code. A high altitude conversion kit,
available from the manufacturer and approved for this purpose,
must be used.
Installation and Operation in Extremely Cold Weather Areas
In areas where extremely cold (below – 20°F) outdoor temperatures
can be expected, some additional installation and operating
precautions should be taken. The following precautions are taken
to prevent possible vent system ice blockage that could result in
safety shutdown of the burners:
1. Adjust to the highest achievable temperature rise within
the rise and static pressure ranges specified on the rating
plate. Depending on specific model, it may be possible to
change to a lower heating blower speed tap to get a higher
temperature rise. This also increases comfort.
2. Make sure there are no leaks of outside air into the return
air system.
3. Keep the outside louver grille as free as possible of any ice
that may form and obstruct the flue outlet.
START-UP
For Your Safety Read Before Lighting
If you do not follow these instructions exactly, a fire or
explosion may result causing property damage, personal
injury, or loss of life.
WARNING
This furnace is equipped with a direct ignition control. Do
not attempt to manually light the burners.
CAUTION
To Shut Down Main Burners
1. Turn off electrical power to unit.
2. Move the ON/OFF switch to the “OFF” position
(see Figure 4).
To Light Main Burners
1. Turn off electrical power to unit.
2. Turn the thermostat to lowest setting.
3. Move the gas valve ON/OFF switch to the “ON” position (see
Figure 4).
4. Turn on electrical power to the unit.
5. Set the room thermostat to the desired temperature.
(If the thermostat “set” temperature is above room
temperature after the pre-purge time expires, main burners
will light.)
Gas Valve
Figure 4
Gas Inlet
ON/OFF
SWITCH
Gas Inlet
Pressure
test tap
Regulator
adjustment
Screw
(Under Cap)
Gas manifold
Pressure test
tap
