64
Gas Heating
Make sure all gas supply lines have been
purged of air before turning on the electrical
power switch. Turn the gas valve to the on
position (see startup instructions). Turn the
main electrical power on and set the controls
to the heating mode of operation.
The combustion ventilation motor should
operate. The control will automatically
supply energy to the igniter and the gas valve
after the heating call is made.
The flame sensing probe detects the presence
of the flame. Should no flame be detected in
10 seconds, the ignition system will recycle.
If no flame is detected after 3 tries, ignition
system will lockout.
Remove the call for heating. The main gas
valves should be extinguished.
The supply fans are controlled by the ignition
system. In the fan “Auto” mode the fan
comes on 45 seconds after the flame is proved
and goes off 120 seconds after the heating
call is removed.
Furnace combustion ventilation air and flue
openings should be checked annually for
debris and obstructions. If vent extensions are
used
they
must
meet
category
IV
requirements.
This appliance contains a wire screen at the
vent outlet. Each heating season, prior to
placing the appliance in heat mode
maintenance check that no debris or foreign
matter has accumulated in the vent outlet. A
good practice is to check for debris each time
the air filters are changed.
In the event the vent outlet becomes blocked
do not attempt to start the appliance in heat
mode until the entire vent opening is cleared.
In the event the unit shut down because the
vent was blocked a qualified technician or
service agency should monitor the unit prior
to re-starting.
The gas burner and heat exchanger should
never require cleaning. If cleaning is
necessary, this indicates faulty operation of
the unit. Cleaning should only be done by a
qualified service agency and only after
consultation
with
an
AAON
service
representative.
If induced draft blower/motor assembly has
to be replaced, care must be taken to provide
an airtight seal between the blower housing
and the burner box.
Once a year, before the unit is in
operation for the heating season, a
qualified service technician should
inspect all flue product carrying areas
of the furnace and main burners for
continued safe operation.
WARNING
LEAK CHECK GAS PIPE
The gas pipe in the unit should be
checked for leaks before startup. Leak
checking is the responsibility of the
installing contractor. All connections
should be checked for leaks annually
after installation. Failure to leak check
could result in fire, explosion, or other
hazardous situations.
DANGER
