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TABLE 25
Manifold and Operating Signal Pressures in inches 0 − 7500 ft (0 − 2286 m)
SLP98
Firing
Rate
Manifold Pressure Nat Gas
Manifold Pressure LP/Propane
Operating Pressure Signal
(Delta P)
Min
Normal
Max
Min
Normal
Max
Min
Normal
Max
35%
0.4
0.5
0.6
1.2
1.5
1.8
0.25
0.30
0.35
70%
1.7
1.9
2.1
5.1
5.5
5.9
0.60
0.65
0.70
100%
3.2
3.5
3.8
9.5
10.0
10.5
1.10
1.15
1.20
NOTE
− A natural to LP/propane gas changeover kit (table 28) is necessary to convert this unit. Refer to the changeover kit
installation instruction for the conversion procedure.
Proper Combustion
Furnace should operate a minimum of 15 minutes with cor-
rect manifold pressure and gas flow rate before checking
combustion. Take combustion sample beyond the flue out-
let and compare to the tables below. The maximum carbon
monoxide reading should not exceed 50 ppm.
TABLE 26
High Fire
Model Input Size
CO
2
%
For Nat
CO
2
%
For L.P.
070
7.6 − 8.6
9.1 − 10.1
090
110
135
TABLE 27
Low Fire
Model Input Size
CO
2
%
For Nat
CO
2
%
For L.P.
070
5.7
7.2 − 8.2
090
5.3 − 6.3
6.8 − 7.8
110
135
High Altitude Information
NOTE
− In Canada, certification for installations at eleva-
tions over 4500 feet (1372 m) is the jurisdiction of local au-
thorities.
SLP98UHV units require no manifold pressure adjust-
ments for operation at altitudes up to 10,000 feet (3048 m)
above sea level. Units installed at altitude of 7,501 to
10,000 feet (2287 to 3048m) require a pressure switch
change per table 28. Table 28 also lists conversion kit re-
quirements.
The® combustion air pressure switch is factory−set and re-
quires no adjustment.
TABLE 28
Conversion Kit Requirements
Model
Input
Size
LP/Propane
Kit
High Altitude Pressure Switch Kit
0 − 10,000
(0 − 3048 m)
0 − 7,500
(0 − 2286 m)
7,501 − 10,000
(2287 − 3048m)
070
65W77
Not required
93W75
090
110
135
Other Unit Adjustments
Primary Limit
The primary limit is located on the heating compartment
vestibule panel. This limit is factory set and require no ad-
justment.
Flame Rollout Switches (Two)
These manually reset switches are located on the inside of
the burner box. If tripped, check for adequate combustion
air before resetting.
