Boiler Manual
Part Number 550-110-593/1099 67
Ratings13b1.See Table 7 for available pilot systems. The suffix shown
in the table is added to the boiler model number. (Not
available for millivolt systems.)
2. Based on standard test procedures prescribed by the
United States Department of Energy.
3. Net I=B=R ratings are based on net installed radiation of
sufficient quantity for the requirements of the building
and nothing need be added for normal piping and pickup.
Ratings are based on a piping and pickup allowance of
1.15. An additional allowance should be made for unusual
piping and pickup loads.
Notes
Install CGa boilers for residential radiant panel systems, converted gravity heating systems or other low water
temperature applications per instructions in this manual to avoid damage due to condensation.
CGa boilers are CSA design certified for installation on combustible flooring.
CGa boilers are ASME rated for 50 psig working pressure.
Table 7 Ignition system model suffixes
DOE
Boiler
model
number
Input
(Btuh)
DOE
Heating
capacity
(Btuh)
0–2,000 feet
altitude
2,000–4,500 feet
altitude
Net
I=B=R
ratings
(Btuh)
Boiler
water
content
(gallons)
DOE
Seasonal efficiency
(% A.F.U.E)
Chimney
and
breeching
size
Input
(Btuh)
Output
(Btuh)
Input
(Btuh)
Output
(Btuh)
SPDN SPDL PIDN
(Note 1) (Note 2) (Note 3)
CGa-25 52,000 44,000 52,000 44,000 46,800 39,000 38,000 1.5 81.5 83.3 84.0 4"I.D. x 20’
CGa-3 70,000 59,000 70,000 59,000 63,000 53,000 51,000 1.5 81.6 83.7 84.0 4"I.D. x 20’
CGa-4 105,000 88,000 105,000 88,000 94,500 79,000 77,000 2.1 81.7 83.7 84.0 5"I.D. x 20’
CGa-5 140,000 117,000 140,000 117,000 126,000 105,000 102,000 2.7 81.8 83.7 83.5 6"I.D. x 20’
CGa-6 175,000 146,000 175,000 146,000 157,500 131,000 127,000 3.3 81.9 83.6 83.2 6"I.D. x 20’
CGa-7 210,000 175,000 210,000 175,000 189,000 157,000 152,000 3.8 82.0 83.6 83.0 7"I.D. x 20’
CGa-8 245,000 204,000 245,000 204,000 220,500 183,000 177,000 4.4 82.1 83.6 82.7 7"I.D. x 20’
Pilot ignition system Natural gas Propane gas
Standing pilot SPDN SPDL
Spark-ignited pilot PIDN Not available