10
Gas Control Valve
4. Turn on the gas supply at the manual gas shutoff valve. Set
the room thermostat to a point above room temperature to
light the main burners.
NOTE: This furnace is equipped with an ignition device,
which automatically lights the burner. This furnace cannot be
lighted manually. Do not try to light the burner by hand.
5. Turn on the electrical power to the furnace.
6. Check minimum inlet gas supply pressure.
■
Turn on all other gas appliances.
■
Observe the pressure rating on the pressure gauge.
■
The minimum inlet gas supply pressure is 5" W.C. for
Natural gas and 11" W.C. for propane gas.
7. Check maximum inlet gas supply pressure.
■
Turn off all other gas appliances.
■
Observe the pressure reading on the pressure gauge.
■
The maximum inlet gas supply pressure is 10.5" W.C. for
Natural gas and 13" W.C. for propane gas.
IMPORTANT: If the inlet gas supply pressure is not within the
minimum and maximum range as shown on the rating plate,
contact your gas supplier.
8. Turn off the electrical power to the furnace.
9. Turn off the gas supply at the manual gas shutoff valve.
Remove the pressure gauge tube and the
¹⁄₈
" hose connector.
10. Replace the inlet pressure tap plug on the gas control valve.
11. Turn on the gas supply at the manual gas shutoff valve.
12. Test all connections by brushing on an approved
noncorrosive leak-detection solution. Bubbles will show a
leak. Correct any leak found.
■
At test pressures greater than
¹⁄₂
psig (3.5 kPa), the
furnace and the manual gas shutoff valve must be
disconnected from the gas supply piping system.
■
At test pressures less than or equal to
¹⁄₂
psig (3.5 kPa),
the furnace must be isolated from the gas supply piping
system by closing the manual gas shutoff valve.
13. Replace the burner access panel.
Check the Furnace Input Rate
(if required)
IMPORTANT:
■
The furnace input rate must not exceed the input rating on
the furnace rating plate.
■
This furnace is equipped for rated input at manifold pressures
of 3.5" W.C. for Natural gas and 11.0" W.C. for propane gas.
■
At altitudes above 4,500 ft the furnace input rate must not
exceed that on the furnace rating plate reduced by 4 percent
for each 1,000 ft above sea level.
1. For Natural gas, check the furnace rate by observing the gas
meter, making sure all other gas appliances are turned off.
The test hand on the meter should be timed for at least one
revolution.
2. The actual heating value of your gas can be obtained from
your local utility company.
NOTE: If the input exceeds the input rating on the furnace rating
plate, adjust the manifold pressure.
Adjust Manifold Pressure
1. Remove the burner access panel.
2. Turn off the gas supply at the manual gas shutoff valve. Use
only your hand to move the gas control knob; tools are not
required.
3. Remove the outlet pressure tap plug on the gas control valve
and connect pressure gauge to the
¹⁄₈
" NPT outlet pressure
tap.
4. Be sure the manual gas shutoff valve has been in the Off
position for at least 5 minutes before starting the furnace.
5. Turn on the gas supply at the manual gas shutoff valve.
NOTE: This furnace is equipped with an ignition device,
which automatically lights the burner. This furnace cannot be
lighted manually. Do not try to light the burner by hand.
6. Turn on the electrical power to the furnace.
7. Set the room thermostat to a point above room temperature
to light the main burners.
8. Observe the pressure reading on the pressure gauge.
9. Refer to the rating plate for the correct manifold pressure. If
necessary, remove the regulator adjusting cap on the gas
valve and turn the regulator adjusting screw clockwise to
increase pressure, or counterclockwise to decrease pressure.
IMPORTANT: If the manifold pressure cannot be adjusted to
the value on the furnace rating plate, contact your gas
supplier.
10. Turn off the gas supply at the manual gas shutoff valve.
11. Disconnect the pressure gauge from the
¹⁄₈
" NPT outlet
pressure tap.
12. Replace outlet pressure tap plug and the regulator adjusting
cap on the gas valve.
A. Regulator adjusting cap
B. NPT inlet
C.
¹⁄₈
" NPT inlet pressure tap
D.
¹⁄₈
" NPT outlet pressure tap
E. NPT outlet
F. Gas control switch
A
B
C
D
E
F
BTU/HR
INPUT
= Cubic feet per Revolution x 3600 x Heating
Value
# Seconds per Revolution
