Instruction manual
Part number 550-142-056/0411
99
GWC gas-fired water boiler — Boiler Manual
Figure 104 Boiler dimensional and physical data (see Figure 103, page 98)
Boiler
model
Supply
Return
Length
L
Gas
connection
size
(Note 1)
Electrical
service
required
(includes
the internal
circulators)
Boiler
water
content
Approx.
shipping
weight
(inches NPT
male)
(inches NPT
female)
(inches) (inches NPT
female)
(amperes) (gallons) (pounds)
GWC-070
1 1 30¾ ½ 15 3.8 313
GWC-105
1 1 30¾ ½ 15 4.7 353
GWC-140
1 1 37¾ ½ 15 6.0 423
GWC-175
1 1 37¾ ½ 15 6.9 464
Note 1: Gas piping from meter to boiler to be sized per local utility requirements.
Figure 105 Boiler ratings
DOE
Boiler
model
CSA
Input
DOE
Heating
capacity
(Note 1)
Net I=B=R
water
rating
(Note 2)
AFUE
(Note 1)
Vent/
combustion
air diameter
Boiler
water
content
% Input derate vs vent length
(Values shown are at maximum vent/air pipe length)
(Note 3)
Direct Exhaust Venting Direct Vent Venting
MBH MBH MBH % Inches Gallons Natural gas Propane Natural gas Propane
GWC-070
70 65 56 91.9
3" PVC 3.8
up to 0.7% up to 1.4% up to 1.5% up to 2.8%
GWC-105
105 97 84 91.2
3" PVC 4.7
up to 1.0% up to 2.2% up to 4.0% up to 5.4%
GWC-140
140 130 113 91.4
3" PVC 6.0
up to 4.0% up to 4.0% up to 7.0% up to 8.0%
GWC-175
175 161 140 91.0
3" PVC 6.9
up to 4.0% up to 4.5% up to 7.0% up to 10.0%
Notes:
1. Based on standard test procedures prescribed by the United States Department of Energy. Ratings also
referred to as CSA Output. NOTE that only DOE Heating Capacity and AFUE are certified by AHRI. AFUE is
also know as Annual Fuel Utilization Efficiency or Seasonal Efficiency.
2. 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 and are determined under the provisions governing forced draft boiler-burner units. An additional
allowance should be made for unusual piping and pickup loads.
3. All of the boilers will automatically de-rate as vent length increases, due to the pressure loss through the vent.
For vent/air pipe lengths less than the maximum, the derate equals the value above times vent length ÷ 100.
4. Boilers are tested for 50 PSIG working pressure.
5. GWC boilers are not available for millivolt systems.
Dimensions and ratings (continued)