STARTUP AND OPERATIONAL CHECKOUT
Do not use this furnace as a construction heater.
Use of this furnace as a construction heater
exposes the furnace to abnormal conditions,
contaminated combustion air and the lack of air
filters. Failure to follow this warning can lead to
premature furnace failure and/or vent failure which
could result in a fire hazard and/or bodily harm.
The automatic gas valve controls the flow of gas to
the main burners. The control circuit built into the
automatic valve body has 2 positions: "OFF" and "ON"
(Figure 27). To shut off gas manually: Switch from "ON"
to "OFF" position. When in "OFF" position, the main
burners are extinguished.
This furnace is equipped with an automatic hot-
surface ignition control and does not require the manual
lighting for furnace operation.
Figure 27
GAS CONTROL DIAGRAM
Do not attempt to manually light the burners.
Failure to follow this warning can lead to electrical
shock that could result in bodily harm.
After the ductwork connections have been made, gas
piping and electrical wiring completed and the furnace
has been properly vented, the unit should be started and
adjusted for proper operation. Check off the following
steps as they are completed.
1.
Be sure all electrical power is OFF.
2.
Check all wiring using proper wiring diagram on
inside of the control box cover.
3.
Turn ON the electrical power.
4.
Set the ignition system control switch in the "ON"
position.
5.
Set the thermostat above room temperature.
6.
The hot-surface ignitor will heat-up to an "orange"
glow, the main burners will ignite.
Figure 28
TYPICAL FLAME APPEARANCE
(MAIN BURNERS)
7.
Recheck for leaks in the manual shut off valve, gas
control valve and gas connections using a soap
solution.
Never use an open flame when testing for gas
leaks! Use of an open flame could lead to a fire or
explosion.
Many soaps used for leak testing are corrosive to
certain metals. Piping must be rinsed thoroughly
with clean water after leak check has been
completed.
Direct Vent (2 Pipe) Manifold Pressure Check:
The burner box static pressure varies with the
different inlet vent pipe lengths and ambient air
conditions. Therefore, the gas valve regulator must be
able to reference the burner box pressure to maintain a
constant manifold setting. The reference tube vent port
on the gas valve has a barbed fitting. Connect this port,
using a tee fitting, to the burner box and pressure switch,
as seen in Figure 29.
When setting or checking the gas valve outlet
manifold pressure, the manometer must be connected to
the gas valve outlet pressure tap and the burner box
pressure hose, as seen in Figure 29.
The actual manifold pressure will be higher than the
reading indicated if the burner box hose is not connected.
The difference will be equal to the burner box static
pressure.
20558801
Issue 0442
Page 23 of 32
Summary of Contents for Gas-Fired Furnace
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Page 21: ...Figure 8 20558801 Issue 0442 Page 13 of 32 VENT TERMINATION CLEARANCES ...
Page 36: ...SEQUENCE OF OPERATION DIRECT IGNITION SYSTEM CONTROL 20558801 Issue 0442 Page 28 of 32 ...
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