Instructions
1)
Locate the 1/8” output pressure tap on the valve (See
FIGURE 6
, page
12). With the manual valve turned off to prevent flow to the gas valve,
connect a manometer to the 1/8” pipe outlet pressure tap in the valve.
NOTE:
A manometer (fluid-filled gauge) is recommended rather than
a spring type gauge due to the difficulty of maintaining calibration of a
spring type gauge.
2)
Open the manual valve and operate the heater. Depress and hold the
door safety switch. Cycle the burner once or twice to properly seat the
adjustment spring in the valve. Measure the outlet pressure of the gas
valve.
Normally when operating on natural gas at sea level, adjustments
should not be necessary to the factory setting. (For high altitude set
-
tings, see next paragraph.)
If adjustment is necessary, remove the cap from the adjustment
screw(s). Set pressure to correct settings by turning the regulator
screw IN (clockwise) to increase pressure. Turn regulator screw OUT
(counterclockwise) to decrease pressure.
Check Valve Outlet
Pressure (can only be
done after heater is
operating)
NOTE:
If operating at high
altitude, outlet pressure
requires adjustment. Follow
instructions below.
Derate by Valve Outlet
Pressure Adjustment for
High Altitude Operation
Instructions for High Altitude Derate
1.
Determine the required valve outlet pressure for the elevation where
the heater will be operating. If unsure of the elevation, contact the local
gas supplier.
Before attempting to measure or adjust valve outlet gas pressure, the inlet
supply pressure
must
be within the specified range both when the heater is
in operation and on standby. Incorrect inlet pressure could cause excessive
valve outlet gas pressure immediately or at some future time. If natural gas
supply pressure is too high, install a regulator in the supply line before it
reaches the heater. If natural gas supply pressure is too low, contact your
gas supplier.
Altitude
Natural Gas
Propane
Feet
Meters
inches w.c.
Manifold Pressure Settings by Altitude for the UNITED STATES
0-2000
0-610
3.5
10.0
2001-3000
611-915
3.1
8.8
3001-4000
916-1220
3.0
8.5
4001-5000
1221-1525
2.8
8.1
5001-6000
1526-1830
2.7
7.7
6001-7000
1831-2135
2.6
7.4
7001-8000
2136-2440
2.5
7.1
8001-9000
2441-2745
2.4
6.7
9001-10000
2746-3045
2.2
6.4
Manifold Pressure Settings by Altitude for CANADA
0-2000
0-610
3.5
10.0
2001-4500
611-1373
2.8
8.1
2.
Locate the 1/8” output pressure tap on the valve (See
FIGURE 6
).
Turn
the knob on the top of the valve to “OFF”. Connect a manometer to the
1/8” pipe outlet pressure tap in the valve. Use a water column manom-
eter that is readable to the nearest tenth of an inch.
NOTE: This adjustment can
only be done after the heater
is in operation. High altitude
adjustment is included in the
startup procedures.
Valve Outlet Pressure
Settings by Elevation
CAUTION: DO NOT
bottom out the gas
valve regulator adjust
-
ing screw. This can
result in unregulated
manifold pressure
causing excess
overfire and heat
exchanger failure.
Form I-UEAS, P/N 221232 R6, Page 11
