Page 13 of 20
507389-02
Issue 1733
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.
To Shut Down Main Burners
1. Turn off electrical power to unit.
2. Move the ON/OFF switch to the “OFF” position (see
Figure 9. Gas Valve
Gas Inlet
ON/OFF
Switch
Gas Inlet
Pressure
Test Tap
Regulator
Adjustment Screw
(under cap)
Gas Manifold
Pressure Test
Tap
Operation
Operation of the unit is automatic and will provide heating
and cooling depending on the setting of the thermostat.
Heating
1. Turn on main power supply.
2. Open manual gas shutoff valve.
3. Set thermostat system to “HEAT”.
4. Set thermostat to temperature desired.
Cooling
1. Turn on main power supply.
2. Set thermostat system switch to “COOL”.
3. Set thermostat to temperature desired.
Heating Sequence of Operation
1. Thermostat calls for heat.
2.
Combustion blower starts and proper air flow is proven
by the pressure switch closing.
3. Blower continues to operate for 30 seconds prior to
the burners lighting.
4.
Ignition control begins spark and opens gas valve. The
burners are lit. Ignition is proved through the flame
sensor.
5. Circulating air blower starts 30 seconds after the
burners light.
6.
When the thermostat is satisfied, the burners and
combustion blower shut off.
7. Circulating air blower will shut off 120 seconds later.
If the burners should fail to ignite, the ignition control will
try to ignite the burners a total of three times. Should the
burners fail to ignite within the three trials for ignition, the
ignition control will lock out for 1 hour before beginning
another ignition cycle. To reset the control, turn the
thermostat down or off for 10 seconds and then set to
desired setting. At this time, the ignition sequence will try
again.
Blower Control
The blower will start approximately 30 seconds after the
burners ignite and will stop approximately 120 seconds
after the thermostat is satisfied. The time delay is preset at
the factory and timing can not be adjusted.
Cooling Sequence of Operation
When the thermostat system switch is set for “COOL”, the
blower will start 5 seconds after the thermostat calls for
cooling and will stop 90 seconds after the thermostat is
satisfied.
Continuous Fan Operation
Continuous operation of the air handling blower will be
obtained if the thermostat fan switch is set to “ON”. With
the thermostat fan switch set to “AUTO”, the air handling
blower will cycle corresponding with the thermostat cycling.
To Shut Down Unit
For temporary or short periods of shutdown, set the
thermostat system switch to “OFF”. For a prolonged period
of shutdown, set the thermostat system switch to “OFF”
and turn off the electrical power supply and the gas supply
to the unit.
