Reznor UDBS Unit Installation Manual - Manual (Page 15)

Form I-UDB, P/N 202658 R14, Page 15
2. Locate the 1/8” output pressure tap on the valve (See FIGURE 10, page 14). Turn
the knob or switch 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 manometer that is
readable to the nearest tenth of an inch.
3. Single-Stage and Two-Stage High Fire - Turn the knob or move the switch on
the top of the valve to “ON”. Remove the cap from the pressure adjusting screw
and adjust the gas train pressure to the pressure selected from the table above.
Adjust pressure by turning the regulator screw IN (clockwise) to increase pressure
or OUT (counterclockwise) to decrease pressure.
Two-Stage Low Fire - Disconnect the wire from the “HI” terminal on the gas valve
and check the low fire pressure. Turn the regulator screw to adjust the low fire outlet
pressure to the “Low Fire” pressure selected from the table. Re-connect the wire to
the gas valve.
4. Turn up the thermostat. (NOTE: On Model UDBS, 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(s). When the outlet pressure is right for the installation,
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 propane 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 specified range, the inlet pressure must be corrected and Steps 3
and 4 repeated.
6. Find the High Altitude Adjustment label in the plastic bag that contained these
instructions. 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 conspicuous 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).
Manifold Pressure Settings by Altitude for CANADA
Altitude Natural Gas (inches w.c.) Propane Gas (inches w.c.)
Feet Meters
Single-Stage and
Two-Stage High Fire
Two-Stage
Low Fire
Single-Stage and
Two-Stage High Fire
Two-Stage
Low Fire
0-2000 0-610 3.5 1.8 10.0 5.0
2001-4500 611-1373 2.8 1.5 8.1 4.1
High Altitude
Capacity Changes
BTUH Inputs and Capacities by Altitude in the UNITED STATES for Model UDBP and Model UDBS
ALTITUDE
Normal
Input
Thermal Output
Capacity
Minimum
Input
Normal
Input
Thermal Output
Capacity
Minimum
Input
Normal
Input
Thermal Output
Capacity
Minimum
Input
Normal
Input
Thermal Output
Capacity
Minimum
Input
Feet Meters Size 30 Size 45 Size 60 Size 75
0-2000 0-610 30000 24600 30000 45000 37350 45000 60000 49800 42000 75000 62250 52500
2001-3000 611-915 28200 23124 28200 42300 35109 42300 56400 46812 39480 70500 58515 49350
3001-4000 916-1220 27600 22632 27600 41400 34362 41400 55200 45816 38640 69000 57270 48300
4001-5000 1221-1525 27000 22140 27000 40500 33615 40500 54000 44820 37800 67500 56025 47250
5001-6000 1526-1830 26400 21648 26400 39600 32868 39600 52800 43824 36960 66000 54780 46200
6001-7000 1831-2135 25800 21156 25800 38700 32121 38700 51600 42828 36120 64500 53535 45150
7001-8000 2136-2440 25200 20664 25200 37800 31374 37800 50400 41832 35280 63000 52290 44100
8001-9000 2441-2745 24600 20172 24600 36900 30627 36900 49200 40836 34440 61500 51045 43050
9001-10000 2746-3045 24000 19680 24000 36000 29880 36000 48000 39840 33600 60000 49800 42000
Feet Meters Size 100 Size 125 Size 150 Size 175
0-2000 0-610 105000 88200 73500 120000 100800 84000 150000 124500 105000 175000 145250 122500
2001-3000 611-915 98700 82908 69090 112800 94752 78960 141000 117030 98700 164500 136535 115150
3001-4000 916-1220 96600 81144 67620 110400 92736 77280 138000 114540 96600 161000 133630 112700
4001-5000 1221-1525 94500 79380 66150 108000 90720 75600 135000 112050 94500 157500 130725 110250
5001-6000 1526-1830 92400 77616 64680 105600 88704 73920 132000 109560 92400 154000 127820 107800
6001-7000 1831-2135 90300 75852 63210 103200 86688 72240 129000 107070 90300 150500 124915 105350
7001-8000 2136-2440 88200 74088 61740 100800 84672 70560 126000 104580 88200 147000 122010 102900
8001-9000 2441-2745 86100 72324 60270 98400 82656 68880 123000 102090 86100 143500 119105 100450
9001-10000 2746-3045 84000 70560 58800 96000 80640 67200 120000 99600 84000 140000 116200 98000