13
6. Turn the gas control valve knob to the OFF position.
Do not force. (Figure 11)
7. Wait five minutes to clear out any gas.
8. Smell for gas, including near the ground. This is
important because some types of gas are heavier
than air. If you have waited five minutes and you do
smell gas, immediately follow the instructions on
the Page 2 of this manual. If having waited for five
minutes and no gas is smell is noted, turn the gas
control valve knob to the ON position. (Figure 11)
9. Replace the heat exchanger door on the side of the
unit.
10. Open the manual gas valve external to the unit.
11. Turn on the electrical power supply to the unit.
12. Set the thermostat to desired setting.
Gas Input And Pressures
Gas supply pressure and manifold pressure with the
burners operating must be as specified on the rating
plate.
Checking Gas Pressure
Gas inlet pressure should be checked and adjusted in
accordance to the type of fuel being consumed.
With Power And Gas Off:
1. Connect a water manometer or adequate gauge to
the inlet pressure tap of the gas valve.
Inlet gas pressure can also be measured by removing
the cap from the dripleg and installing a predrilled cap
with a hose fitting. (Figure 12)
With Power And Gas On:
2. Put unit into heating cycle and turn on all other gas
consuming appliances.
Figure 12
Measuring Inlet Gas Pressure
Alternate Method
Secondary Limit Control
On the PGB**C & PGD**C series, a second limit control
is placed on the blower scroll. This control will open due
to elevated temperature caused by the blower failing.
The reason for elevated temperatures at the control
should be determined and repaired prior to resetting
this manual reset control. The secondary limit control is
located on the top of the blower scroll assembly. (Figure
10).
If the power to the unit is interrupted during the heating
cycle, it may cause the secondary limit to trip. To reset,
press the red button on the limit.
Blower
Compartment
Access Door
Blower
Assembly
Secondary
Limit Control
Reset Button
C
o
n
d
en
ser
C
o
il
Du
c
t
O
p
en
in
g
Figure 10
Secondary Limit Control
Operating Instructions (Heating)
NOTE: Figure 2 illustrates the proper gas valve mount-
ing location.
OFF
ON
Figure 11
Gas Valve (Top View)
1. Close the manual gas valve external to the unit.
2. Turn off the electrical power supply to the unit.
3. Set the room thermostat to its lowest possible set-
ting.
4. Remove the heat exchanger door on the side of the
unit by removing screws.
5. This unit is equipped with an ignition device which
automatically lights the pilot. Do NOT try to light
burner by any other method.