4
Part Number 550-142-785/0812
GWI
Series 2
Gas-Fired Water Boilers –
Boiler Manual
1 Prepare boiler location
continued
Failure to follow all instructions can result in flue gas
spillage and carbon monoxide emissions, causing
severe personal injury or death.
When removing boiler from existing common vent system:
At the time of removal of an existing boiler, the following steps
shall be followed with each appliance remaining connected to
the common venting system placed in operation, while the other
appliances remaining connected to the common venting system
are not in operation.
a. Seal any unused openings in the common venting system.
b. Visually inspect the venting system for proper size and hori
-
zontal pitch and determine there is no blockage or restriction,
leakage, corrosion or other deficiencies which could cause an
unsafe condition.
c. Test vent system — Insofar as is practical, close all building
doors and windows and all doors between the space in which
the appliances remaining connected to the common venting
system are located and other spaces of the building. Turn
on clothes dryers and any appliance not connected to the
common venting system. Turn on any exhaust fans, such as
range hoods and bathroom exhausts, so they will operate at
maximum speed. Do not operate a summer exhaust fan. Close
fireplace dampers.
d. Place in operation the appliance being inspected. Follow the
lighting/operating instructions. Adjust thermostat so appliance
will operate continuously.
e. Test for spillage at draft hood relief opening after 5 minutes of
main burner operation. Use the flame of a match or candle.
f. After it has been determined that each appliance remaining
connected to the common venting system properly vents when
tested as outlined above, return doors, windows, exhaust fans,
fireplace dampers, and any other gas-burning appliance to
their previous conditions of use.
Any improper operation of common venting system should be
corrected so the installation conforms with the National Fuel
Gas Code, ANSI Z223.1 – latest edition. Correct by resizing to
approach the minimum size as determined using the appropriate
tables in Part 11 of that code. Canadian installations must comply
with B149.1 or B149.2 Installation Code.
Chimney draft vent requirements
1. Venting must be installed according to Part 7, Venting of
Equipment, of National Fuel Gas Code, ANSI Z223.1-latest
edition and applicable building codes. Canadian installations
must comply with B149.1 or B149.2 Installation Codes.
2. Chimney or vent termination:
• A chimney, or any vent other than a Type B vent with listed
vent cap, must extend at least 3 feet above the highest
point where it passes through a roof of a building, and at
least 2 feet higher than any portion of a building within a
horizontal distance of 10 feet.
• Type B vents with listed caps may terminate as in Figure 2
if no closer than 8 feet from a vertical wall or similar ob
-
struction.
• Otherwise, Type B vents must terminate at least 2 feet
above the roof penetration and at least 2 feet higher than
any portion of a building within 10 feet.
3. A lined chimney is preferred and must be used when required
by local, state, provincial and national codes, laws, regulations
and ordinances. Vitreous tile linings with joints that prevent
retention of moisture and linings made of noncorrosive materi
-
als are best. Advice for flue connections and chimney linings
can be obtained from local gas utility. Type B double-wall metal
vent pipe or single-wall vent pipe may be used as a liner.
4. Cold masonry chimneys, also known as outside chimneys,
typically have one or more walls exposed to outside air.
When any atmospheric gas-fired boiler with automatic vent
damper is vented through this type of chimney, the potential
exists for condensation to occur. Condensation can damage
a masonry chimney. Manufacturer recommends the following
to prevent possible damage.
a. Line chimney with corrosion-resistant metal liner such as
AL29-4C® single-wall stainless steel or B-vent. Size liner
per National Fuel Gas Code ANSI Z223.1–latest edition.
b. Provide drain trap to remove any condensate.
5. Where two or more gas appliances vent into a common chim-
ney or vent, equivalent area should be at least equal to area of
vent outlet on largest appliance plus 50 percent of vent outlet
area of additional appliance.
Direct exhaust venting (Category III) — DO NOT
COMMON
vent the GWI in a direct exhaust system
(Category III). Connecting more than one appliance
to a direct exhaust system will cause flue gas spill
-
age or appliance malfunction, resulting in possible
severe personal injury, death or substantial property
damage.
Inspect existing chimney before installing boiler.
Failure to clean or replace perforated pipe or tile
lining will cause severe personal injury or death.
Vent system
GWI boilers can be either chimney draft vented
or direct-exhaust vented. See
pages 7 to 12
for
detailed installation instructions.
If you are removing an existing boiler from a shared
venting system and the new GWI boiler will not share
the vent system (allowed only when chimney draft
venting), you must test each remaining appliance
individually to verify the vent system still operates
adequately. Follow guidelines below.
Figure 2 Terminations with Type B vent fitted with listed
cap, provided vent is at least 8 feet from any
vertical wall or similar obstruction.
