Checking Gas Pressure - Daikin APGM3 Service And Troubleshooting

SERVICING
The length of Dimension "A" determines the angle of Gas
Stream Defraction, "B".
A dent or burr will cause severe deflection of gas stream.
No resizing should be attempted until all factors are taken
into consideration such as inlet manifold gas pressure,
alignment, and positioning, specific gravity and BTU
content of the gas being consumed.
The only time resizing is required is when a reduction in
firing rate is required for an increase in altitude.
Orifices should be treated with care in order to prevent
damage. 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 primary air, which will make it difficult to adjust
the flame properly. This same problem can occur if an
orifice spud of a different length is substituted.
Disconnect Gas and electrical power supply.
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.

Checking Gas Pressure

Gas inlet and manifold pressures should be checked and
adjusted in accordance to the type of fuel being consumed.
NOTE: Use adapter kit #0151K00000S to measure gas
pressure on White-Rodgers 36G22 and 36G54 gas
valves.
Disconnect Gas and electrical power supply.
1. Connect a digital manometer or adequate gauge to
the inlet pressure fitting of the gas valve.
DENT OR
BURR
GAS
STREAM B
WARNING
WARNING
2. Remove the pressure tap fitting at the manifold if
provided or check at the gas valve outlet fitting and
connect another manometer or gauge.
Regulator Cover
Screw
10.0
Mode
White Rodgers Model 36G 1-Stage Gas Valve
Outlet
Pressure Boss
Open to
Atmosphere
Inlet
Pressure
Boss
10.0
Mode
White-Rodgers Model 36G54 Connected to Manometer
White Rodgers Model 36G 2-Stage Gas Valve
Measuring Inlet and Manifold Gas Pressure
With power ON:
Line voltage now present.
3. Put furnace into heating cycle and turn on all other
gas consuming appliances.
For NATURAL GAS:
a. Inlet pressure should be a nominal 7" w.c.
b. (2 stage heat models only) Manifold pressure on
low stage should be 2.0" w.c. ± .3" w.c.
c. Manifold pressure for 1 stage heat models and
high stage for 2 stage heat models should be
3.5" w.c. ± .3" w.c.
For PROPANE GAS:
a. Inlet pressure should be a nominal 11" w.c.
b. (2 stage heat models only) Manifold pressure on
low stage should be 6" w.c.
High Fire Regulator
Adjust
Regulator
Low Fire
Regulator
Adjust
Common
Terminal(C)
WARNING
Vent
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