S-306 Checking Orifices; S-307 Checking Gas Pressure - Maytag Amana GMES9 Series Service Instructions Manual

SERVICING
D ALL G
ISCONNECT AS AND
In checking main burners, look for signs of rust, oversized
and undersized carry over ports restricted with foreign ma-
terial, etc, refer to previous drawing. Burner cross-over slots
should not be altered in size.
S-306 CHECKING ORIFICES
Single stage furnaces are factory equipped with #45 gas
orifices.
Orifices should be treated with care in order to prevent dam-
age. They should be removed and installed with a box-end
wrench in order to prevent distortion. In no instance should
an orifice be peened over and redrilled. This will change the
angle or deflection of the vacuum effect or entraining of prima-
ry air, which will make it difficult to adjust the flame properly.
D ALL G
ISCONNECT AS AND
1. Check orifice visually for distortion and/or burrs.
2. Check orifice size with orifice sizing drills.
3. If resizing is required, a new orifice of the same physical
size and angle with proper drill size opening should be
installed.
The length of Dimension "A" determines the angle of Gas
Stream "B".
A dent or burr will cause a severe deflection of the gas stream.

S-307 CHECKING GAS PRESSURE

Gas Supply Pressure Measurement
T
O PREVENT UNRELIABLE OPERATION OR EQUIPMENT DAMAGE, THE
INLET GAS SUPPLY PRESSURE MUST BE AS SPECIFIED ON THE UNIT
RATING PLATE WITH ALL OTHER HOUSEHOLD GAS FIRED APPLIANCES
OPERATING.
50
WARNING
E P S
LECTRICAL OWER UPPLY.
WARNING
E P S
LECTRICAL OWER UPPLY.
A
GAS
STREAM B
DENT OR
BURR
GAS
STREAM B
CAUTION
Gas inlet and manifold pressures should be checked and
adjusted in accordance to the type of fuel being consumed.
The line pressure supplied to the gas valve must be within
the range specified below. The supply pressure can be mea-
sured at the gas valve inlet pressure tap or at a hose fitting
installed in the gas piping drip leg. The supply pressure must
be measured with the burners operating. To measure the gas
supply pressure, use the following procedure.
D
ISCONNECT ELECTRICAL POWER AND SHUT OFF GAS SUPPLY.
1. After turning off gas to furnace at the manual gas shutoff
valve external to the furnace, remove burner compartment
door to gain access to the gas valve.
2. Connect a calibrated water manometer (or appropriate
gas pressure gauge) at either the gas valve inlet pressure
tap or the gas piping drip leg as shown in the following
figures.
NOTE: At either location, a hose fitting must be installed prior
to making the hose connection.
NOTE: Use adapter kit #0151K00000S to measure gas
pressure on White-Rodgers 36G22 gas valves.
GAS LINE
GAS SHUTOFF VALVE
DRIP LEG CAP
WITH FITTING
MANOMETER HOSE
Measuring Inlet Gas Pressure
(Alternate Method)
3. Turn ON the gas and electrical power 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
following table.
INLET GAS SUPPLY PRESSURE
Natural Gas Minimum: 4.5" w.c.
Propane Gas Minimum: 11.0" w.c.
If supply pressure differs from above, make necessary ad-
justments to pressure regulator, gas piping size, etc., and/
or consult with local gas utility.
WARNING
GAS LINE
TO FURNACE
OPEN TO
ATMOSPHERE
MANOMETER
Maximum: 10.0" w.c.
Maximum: 13.0" w.c.