5
Part Number 550-142-320/0720
GWA
Series 3
Gas-Fired Water Boilers –
Boiler Manual
1 Prepare boiler location
continued
To prevent potential of severe personal injury or
death, check for products or areas listed below
before installing boiler. If any of these contami-
nants are found:
• Remove contaminants permanently.
— OR —
• Isolate boiler and provide outside combustion air.
See national, provincial or local codes for further
information.
Please review the following information on potential combus-
tion air contamination problems.
See Table 2
for products and areas which may cause contami-
nated combustion air.
Air contamination
Chimney or vent requirements
1. Venting must be installed according to Part 7, “Venting of
Equipment”, of National Fuel Gas Code, ANSI Z223.1 – lat-
est edition and applicable building codes.
2. See “Ratings” on Page 51 for minimum chimney or vent
sizes. 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 build-
ing, 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 obstruction.
• 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 materials 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 dam-
age a masonry chimney. The following are recommended
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
chimney 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.
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
Products to avoid
Spray cans containing chloro/fluorocarbons
Permanent wave solutions
Chlorinated waxes/cleaners
Chlorine-based swimming pool chemicals
Calcium chloride used for thawing
Sodium chloride used for water softening
Refrigerant leaks
Paint or varnish removers
Hydrochloric acid/muriatic acid
Cements and glues
Antistatic fabric softeners used in clothes dryers
Chlorine-type bleaches, detergents, and cleaning solvents found in
household laundry rooms
Adhesives used to fasten building products and other similar products
Areas likely to have contaminants
Dry cleaning/laundry areas and establishments
Swimming pools
Metal fabrication plants
Beauty shops
Refrigeration repair shops
Photo processing plants
Auto body shops
Plastic manufacturing plants
Furniture refinishing areas and establishments
New building construction
Remodeling areas
Garages with workshops
Table 2 Corrosive contaminants and likely locations
Vent system
continued
