3
5. Turn OFF gas to the unit at the manual shutoff valve and disconnect manometer. Reinstall line pressure tap plug. The
pressure tap must be leak checked after resealing.
GAS TYPE
MIN
MAX
NATURAL
5" w.c.
10" w.c.
L.P.
11" w.c.
13" w.c.
GAS SUPPLY PRESSURE RANGE
Table 2
MANIFOLD PRESSURE CHECK
Refer to table 3 for proper Natural Gas manifold pressure & table 4 for proper L.P. Gas manifold pressure. *For L.P. Gas, the
gas valve outlet pressure is automatically adjusted for LP by installation of the jumper in step 10. Only minor changes to
manifold pressure should be made by adjusting the gas valve pressure regulator. Minor adjustments may be made by
removing the access plug and turning the fine-adjustment screw with 1/8" flat blade screwdriver. Adjustment should only be
done with monitoring outlet pressure with a suitable manometer properly attached to the outlet pressure tap.
1. Turn OFF electrical power
&
gas supply to the unit.
2. Use a 3/16" Allen wrench to remove 1/8" outlet pressure tap from the gas valve.
3. Connect a calibrated water manometer or appropriate gas pressure gauge at the gas valve outlet pressure tap.
4. Turn ON the power and gas, put the unit into heating cycle on high fire (100%).
5. Remove the White cap located on top the gas valve next to the +
&
- symbols.
6. Use a 1/8" flat blade screwdriver to turn the fine adjustment screw, clockwise (+) to increase manifold pressure, counter
clockwise (-) to decrease manifold pressure.
7. After adjustment is made, turn OFF gas to the unit at the manual shutoff valve and disconnect manometer. Reinstall line
pressure tap plug. The pressure tap must be leak checked after resealing.
Natural Gas Manifold Pressure Range
Low Stage
High Stage
.85" w.c. - 1" w.c.
3.2" w.c. - 3.8" w.c.
Table 3
Low Stage
High Stage
2.3" to 2.7" w.c.
9.7" to 10.3" w.c.
Propane Gas Manifold Pressure Range
Table 4
