35
NOTE:
If measuring gas pressure at the drip leg or Honeywell VR9205
gas valve, a field-supplied hose barb fitting must be installed prior to
making the hose connection. If using the inlet pressure tap on the
White-Rodgers 36G54 gas valve, then use the 36G Valve Pressure
Check Kit, Goodman Part No. 0151K00000S.
3.
Turn ON the gas supply and operate the furnace and all other
gas consuming appliances on the same gas supply line.
4.
Measure furnace gas supply pressure with burners firing.
Supply pressure must be within the range specified in the
Inlet Gas Supply Pressure
table.
Natural Gas
Minimum: 4.5" w.c.
Maximum: 10.0" w.c.
Propane Gas
Minimum: 11.0" w.c.
Maximum: 13.0" w.c.
Inlet Gas Supply Pressure
If supply pressure differs from table, make the necessary adjust-
ments to pressure regulator, gas piping size, etc., and/or consult
with local gas utility.
5. Turn OFF gas to furnace at the manual shutoff valve and
disconnect manometer. Reinstall plug before turning on
gas to furnace.
6. Turn OFF any unnecessary gas appliances stated in step
3.
Gas Line
Gas
Shutoff
Valve
Gas Line
To Furnace
Drip Leg Cap
With Fitting
Manometer Hose
Manometer
Open To
Atmosphere
Measuring Inlet Gas Pressure (Alt. Method)
G
AS
M
ANIFOLD
P
RESSURE
M
EASUREMENT
AND
A
DJUSTMENT
T
O
PREVENT
UNRELIABLE
OPERATION
OR
EQUIPMENT
DAMAGE
,
THE
GAS
MANIFOLD
PRESSURE
MUST
BE
AS
SPECIFIED
ON
THE
UNIT
RATING
PLATE
.
O
NLY
MINOR
ADJUSTMENTS
SHOULD
BE
MADE
BY
ADJUSTING
THE
GAS
VALVE
PRESSURE
REGULATOR
.
CAUTION
Only small variations in gas pressure should be made by adjust-
ing the gas valve pressure regulator. The manifold pressure must
be measured with the burners operating. To measure and adjust
the manifold pressure, use the following procedure.
1. Turn OFF gas to furnace at the manual gas shutoff valve
external to the furnace.
2. Turn off all electrical power to the system.
3. Outlet pressure tap connections:
a. Honeywell VR9205 valve: Remove the outlet pressure
tap plug. Install an 1/8" NPT hose barb fitting into the outlet
pressure tap.
b.
White-Rodgers 36G54 valve: Back outlet pressure test screw
(inlet/outlet pressure tap) out one turn (counterclockwise,
not more than one turn).
4.
Attach a hose and manometer to the outlet pressure barb fitting
(Honeywell valve) or outlet pressure tap (White-Rodgers valve).
5.
Turn ON the gas supply.
6.
Turn on power and close thermostat “R” and “W1” contacts to
provide a call for low stage heat.
7.
Measure the gas manifold pressure with burners firing. Adjust
manifold pressure using the
Manifold Gas Pressure
table
shown below.
8. Remove regulator cover screw from the low (LO) outlet
pressure regulator adjust tower and turn screw clockwise
to increase pressure or counterclockwise to decrease
pressure. Replace regulator cover screw.
9.
Close thermostat “R” and “W2” contacts to provide a call for
high stage heat.
10. Remove regulator cover screw from the high (HI) outlet
pressure regulator adjust tower and turn screw clockwise
to increase pressure or counterclockwise to decrease
pressure. Replace regulator cover screw.
11. Turn off all electrical power and gas supply to the system.
12. Remove the manometer hose from the hose barb fitting or
outlet pressure tap.
13. Replace outlet pressure tap:
a. Honeywell VR9205 valve: Remove the 1/8" NPT hose barb
fitting from the outlet pressure tap. Replace the outlet
pressure tap plug and seal with a high quality thread
sealer.
b. White-Rodgers 36G54 valve: Turn outlet pressure test
screw in to seal pressure port (clockwise, 7 in-lb
minimum).
14. Turn on electrical power and gas supply to the system.
15. Close thermostat contacts “R” and “W1/W2” to energize the
valve.
Using a leak detection solution or soap suds, check for leaks at
outlet pressure boss plug (Honeywell valve) or screw (White-Rodg-
ers valve). Bubbles forming indicate a leak. SHUT OFF GAS AND
REPAIR ALL LEAKS IMMEDIATELY!
NOTE:
For gas to gas conversion, consult your dealer for
appropriate conversion.
Gas
Rate
Range
Nominal
Low Stage
1.7 to 2.3" w.c.
2.0" w.c.
High Stage
3.2 to 3.8" w.c.
3.5" w.c.
Low Stage
5.7 to 6.3" w.c.
6.0" w.c.
High Stage
9.7 to 10.3" w.c. 10.0" w.c.
Manifold Gas Pressure
Natural
Propane
G
AS
I
NPUT
R
ATE
M
EASUREMENT
(N
ATURAL
G
AS
O
NLY
)
The gas input rate to the furnace must never be greater than that
specified on the unit rating plate. To measure natural gas input
using the gas meter, use the following procedure.
1. Turn OFF the gas supply to all other gas-burning appliances
except the furnace.
2.
While the furnace is operating, time and record one complete
revolution of the smallest gas meter dial.
