PRE-START CHECK LIST
Complete the following checks before starting the unit.
1. Check the type of gas being supplied. Be sure that it is the
same as listed on the unit nameplate.
2. Make sure that the vent and combustion air hoods have
been properly installed.
OPERATING INSTRUCTIONS
1. STOP! Read the information on the unit safety label.
2. Set the thermostat to the lowest setting.
3. Turn off all electrical power to the unit.
4. DO NOT try to light the burners by hand. This appliance is
equipped with an ignition device which automatically lights
the burners.
5. Remove the access panel.
6. Turn the gas valve manual sellector arm to the “OFF”
position.
7. Wait five (5) minutes to clear out any gas. If you then smell
gas, STOP! Follow “B” in the information on the unit safety
label. If you don’t smell gas, go to the next step.
8. Turn the gas valve manual sellector arm to the “ON”
position.
9. Replace the control access panel.
10. Turn on all electric power to the unit.
11. Set the thermostat to the desired setting.
12. If the unit will not operate, follow the instructions “To Turn
Off Gas To Appliance” and call your service technician or
gas supplier.
TO TURN OFF GAS TO UNIT
1. Set the thermostat to the lowest setting.
2. Turn off all electric power to the appliance if service is to be
performed.
3. Remove the control access panel.
4. Turn the gas valve manual sellector arm to the “OFF”
position. DO NOT FORCE.
5. Replace the control access panel.
POST-START CHECK LIST (GAS)
After the entire control circuit has been energized and the
heating section is operating, make the following checks:
1. Check for gas leaks in the unit piping as well as the supply
piping.
2. Check for correct manifold gas pressures. See “Checking
Gas Input”.
3. Check the supply gas pressure. It must be within the limits
shown on rating nameplate. Supply pressure should be
checked with all gas appliances in the building at full fire.
At no time should the standby gas line pressure exceed 13",
nor the operating pressure drop below 4.5" for natural gas
units. If gas pressure is outside these limits, contact the
local gas utility for corrective action.
MANIFOLD GAS PRESSURE ADJUSTMENT
Small adjustments to the high-fire gas flow may be made by
turning the pressure regulator adjusting screw on the automatic
gas valve. Refer to Figure 6.
Adjust as follows:
1. Remove the cap on the tower. See Figure 6 for location.
2. To decrease the gas pressure, turn the adjusting screw
counterclockwise.
3. To increase the gas pressure, turn the adjusting screw
clockwise.
NOTE: The correct manifold pressure for natural gas furnaces
is 3.5 IWG
±
0.2. The correct manifold pressure for
propane (LP) gas is 10.0 IWG
±
0.2.
BURNER INSTRUCTIONS
To check or change the burners, CLOSE THE MAIN MANUAL
SHUT-OFF VALVE AND SHUT OFF ALL POWER TO THE
UNIT.
1. Open the unit fitting in the supply line. See Figure 3.
START-UP
MANUAL
SELECTOR
ARM
SHOWN
ROBERT SHAW VALVE
1
⁄
2
-14 NPT
(INLET)
PRESSURE
REGULATOR
MANUAL GAS
COCK KNOB
WHITE-RODGERS VALVE
1
⁄
2
-14 NPT
(OUTLET)
MANIFOLD
ADJUSTMENT
SCREW
PRESSURE
REGULA-
FIG. 6 - GAS VALVE
530.44-N5Y
Unitary Products Group
9
