7. Mechanical
(cont’d)
7.1 Gas Piping and
Pressure (cont’d)
FIGURE 6 - Top
View of Valve
showing Outlet
Pressure Tap
and Adjustment
Locations
3.
Turn the knob on the top of the valve to “ON”. Remove the cap from
the output pressure adjusting screw and adjust the gas train pressure
to the pressure selected from the table on page 12. Adjust pressure by
turning the regulator screw IN (clockwise) to increase pressure or OUT
(counterclockwise) to decrease pressure.
4.
Turn up the thermostat. Depress and hold the door safety switch. Cycle
the burner once or twice to properly seat the adjustment spring in the
valve.
Re-check the pressure. When the outlet pressure is right for the instal-
lation, remove the manometer and replace the cap.
Check for leak at the pressure tap fitting.
5.
With the heater operating determine that the inlet pressure to the
heater for natural gas is between 5 and 13.5 inches w.c. and for pro-
pane between 10 and 13.5 inches w.c. Take this reading as close as
possible to the heater (Heaters are equipped with gas valves that
have an inlet pressure tap.) If the inlet pressure is not within the speci
-
fied range, the inlet pressure must be corrected and Steps 3 and 4
repeated.
6.
Find the High Altitude Adjustment label, P/N 197062, in the plastic
bag with this installation manual. Using a permanent marker, fill-in the
appropriate information from the tables below. Select a location for the
label on the outside of the heater access panel so that it will be con-
spicuous to anyone operating or servicing the unit. Be sure the surface
is clean and dry and adhere the label.
The input and/or the capacity of the heater changes with the derate. The
tables below list inputs and capacities at altitudes from sea level to 10,000
ft (3045M).
High Altitude Capacity
Changes
BTUH Inputs and Capacities by Altitude in the UNITED STATES for Model UEAS
ALTITUDE
Normal
Input
Thermal Output
Capacity
Normal
Input
Thermal Output
Capacity
Normal
Input
Thermal Output
Capacity
Normal
Input
Thermal Output
Capacity
Feet
Meters
Size 130
Size 180
Size 260
Size 310
0-2000
0-610
131,000
121,830
175,000
159,250
260,000
239,200
305,000
277,550
2001-3000 611-915
123,140
114,520
164,500
149,695
244,400
224,848
286,700
260,897
3001-4000 916-1220
120,520
112,084
161,000
146,510
239,200
220,064
280,600
255,346
4001-5000 1221-1525 117,900
109,647
157,500
143,325
234,000
215,280
274,500
249,795
5001-6000 1526-1830 115,280
107,210
154,000
140,140
228,800
210,496
268,400
244,244
6001-7000 1831-2135 112,660
104,774
150,500
136,955
223,600
205,712
262,300
238,693
7001-8000 2136-2440 110,040
102,337
147,000
133,770
218,400
200,928
256,200
233,142
8001-9000 2441-2745 107,420
99,901
143,500
130,585
213,200
196,144
250,100
227,591
9001-10000 2746-3045 104,800
97,464
140,000
127,400
208,000
191,360
244,000
222,040
7.1.3 Valve Outlet or Orifice Pressure Setting (cont’d)
Top View - Single-Stage Valve
1/8”
Output
Pressure
Tap
Inlet Pressure
Tap
Output
Adjustment
Screw
Instructions for High Altitude Derate (cont’d)
Form I-UEAS, Page 12
