6
1- VENTING THE COMBINATION HEATER
•
Determine venting method to use.
Refer to appropriate sections for instal-
lation details.
• Use vent materials approved by local
codes for gas-fired appliances. In their
absence refer to:
- National Fuel Gas Code, ANSI
Z223.1.
- In Canada, refer to CAN/CGA B149
Installation Code for Gas Fired
Equipment.
- NFPA 211, Standard for Chimneys,
Fireplaces, Vents and Solid Fuel
Burning Appliances.
1A. Chimney Draft Venting
•
Use galvanized steel vent or equivalent
•
To prevent downdrafts, chimney should
extend at least 2 feet above highest part
of roof or other structures within 30 feet.
•
To vent with another appliance, see
National Fuel Gas Code, ANSI Z223.1,
latest edition.
•
For inside chimney (no walls exposed
to outside).
- Inside of chimney must be lined with
vitreous tile or metal liner.
- Maintain two-inch clearance from
combustible material to vent pipe.
- DO NOT use chimney with open fire-
place.
- Inspect chimney and clean if needed.
- Make horizontal runs as short as possi-
ble. Long runs can cause condensation.
- When longer runs are used, support
with appropriate hangers.
- To prevent blockage, do not vent into
bottom of chimney.
- Vent pipe must not go beyond inside
wall of chimney.
- Vent passing through floors or ceil-
ings must be firestopped.
•
Outside chimney (one or more walls
exposed to outside)
- Can be used for chimney draft vent-
ing only when lined with corrosion
resistant metal liner. Provide con-
densation drain.
- Size liner per ANSI Z223.1.
Increase breeching at the appliance.
- Can be used a raceway for direct
venting.
1B. Direct Venting
When replacing an existing appliance on
common venting system, the vent system
may be too large for remaining appli-
ances. Refer to ANSI Z223.1 for proper
sizing.
Give special attention to location of
Combination Heater vent to avoid possi-
bility of severe personal injury, death, or
substantial property damage.
•
Review “Locating Combination Heater”
to determine location of venting.
•
Use AL29-4C or equivalent vent
material.
1C. Venting Through Cold Areas
•
Extended runs through cold areas could
cause condensation which must be
drained away.
•
Provide a means to trap and drain con-
densation from the vent system. Do not
place drain where freezing could occur.
•
Crimped ends of vent pipe must face
toward appliance.
WARNING
CAUTION
INSTALLATION
