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17 - BOILER RATINGS AND CAPACITIES
PN 240013090 REV. C [10/01/2021]
†
For altitudes above 2,000 ft. rating should be reduced at the rate of 4% for each 1,000 ft. above sea level.
Heating Capacity is based on D.O.E. (Department of Energy) test procedure.
(1)
Add model number suffix ‘P’ for Propane.
(2)
Net AHRI Water rating shown based on piping and pickup allowance of 1.15. Consult manufacturer before
selecting boiler for installations having unusual piping and pickup requirements, such as intermittent
system operation, extensive piping systems, etc.
(3)
MBH = 1,000 Btuh = British Thermal Unit Per Hour
-
Ratings marked “Net AHRI Ratings” indicate amount of remaining heat input used to heat radiation or terminal units.
Net AHRI Ratings shown are based on allowance of 1.15 in accordance with factors shown on AHRI Standard as
published by The Hydronics Institute.
-
Selection of boiler size should be based upon “Net AHRI Rating” being equal to or greater than calculated heat loss of
the building.
-
Consult manufacturer before selecting boiler for installations having unusual piping and pickup requirements.
BOILERS FOR USE AT HIGH ALTITUDE
Boiler is factory equipped for use at altitudes of 0-2,000 feet above sea level.
For use at altitudes above 2,000 feet above sea level, input ratings are reduced by change in main burner orifice size.
For altitudes above 2,000 feet above sea level, input ratings should be reduced at rate of 4% for each 1,000 feet above
sea level. Consult National Fuel Gas Code
(NFPA54/ANSI Z223.1-latest edition), or manufacturer for correct orifice sizing
information.
Table 1 - Ratings and Capacities
BOILER
MODEL
NUMBER
(1)
† NATURAL GAS
† PROPANE GAS
AFUE
Input
(3)
Mbh
Heating
Capacity
(3)
Mbh
(2)
NET AHRI
RATING
Water,
(3)
Mbh
INPUT
(3)
Mbh
HEATING
CAPACITY
(3)
MBH
(2) NET
AHRI
RATING
(3)
Mbh
INTERMITTENT
IGNITION WITH
VENT DAMPER
WPSB-3
75
63
55
70
59
51
84.0
WPSB-4
112
94
82
105
88
77
84.0
WPSB-5
150
126
110
140
118
103
84.1
WPSB-6
187
157
137
175
147
128
84.1
WPSB-7
225
188
163
210
176
153
84.0
WPSB-8
262
221
192
245
208
181
84.0
WPSB-9
299
252
219
280
237
206
84.0
