Manifold Pressure Settings - American Standard *UD Series Operation Manual

Manifold Pressure Settings

The 40" gas furnaces are shipped from the factory
for use with natural gas. Conversion to propane
requires a change in the main burner orifices. The
single stage White-Rodgers gas valve, 36E01, also
requires the installation of an LP regulator spring.
The two stage furnaces (R-Models) with White-Rodgers
gas valve, 36E96, type 211 require a gas valve change
for LP fuel. The two stage gas valve, 36E96 type 227,
used in the UY/ DY-R furnace is a dual purpose
MAIN
BURNER ORIFICE
DRILL SIZE
44
452
55
56 3
1 Applies to single stage models also.
2 Factory change from 44 to 45 orifices in January 1994.
3 LP kit orifices changed from 55 to 56 in August 1994.
Single Stage
(Typical)
M 1
P 3
C 2
NO
OFF
Remove the slotted screw to adjust
manifold pressure. Using a flat blade
screwdriver or allen wrench, turn the
adjustment screw clockwise (in) to
increase pressure and (out) to decrease
gas pressure.
valve and does not require a regulator spring change
for LP conversion.
Note: It is necessary to adjust the "Hi" fire setting
to maximum rate (turn adjustment screw clockwise
until it bottoms) before setting the "Lo" propane fire
rate , otherwise the "Lo" fire rate of 4.0 – 4.5" W.C. cannot
be set above the 3.5" W.C. natural gas "Hi" fire setting.
Models may be an A or T.
TYPE
FUEL
NATURAL
NATURAL
PROPANE
PROPANE
Single Stage
(Toggle Switch)
M1
P3
O
F
F C2
ON
Remove the slotted screw to adjust
manifold pressure. Using a flat blade
screwdriver or allen wrench, turn
the adjustment screw clockwise (in)
to increase pressure and (out) to
decrease gas pressure.
31
FINAL MANIFOLD PRESSURE SETTING
1ST STAGE
1.4-1.7" W.C
1.4-1.7" W.C
4.0-4.5" W.C
4.0-4.5" W.C
Two-Stage
(VAL4564 has Toggle Switch)
ON
OFF
1st Stage (LO) Manifold
Pressure Adjustment
Remove the slotted screw on top
of the gas valve for 1st stage (LO)
manifold pressure adjustment.
Remove slotted screw on outlet
side for 2nd stage (HI) manifold
adjustment.
Turn the adjustment nut clockwise (in)
to increase the gas flow rate, and
counter clockwise (out) to de-crease
the gas pressure using a 3/32" hex
wrench.
2ND STAGE1
3.0-3.2" W.C.
3.0-3.7" W.C.
9.0-9.5" W.C.
10.5-11.0" W.C.
6 3
1
2nd Stage (HI) Manifold
Pressure Adjustment