Venting; Thermometers (Not Supplied) - A.O. Smith BTI-80 Installation, Operation, Service, Maintenance, Limited Warranty

THE INSTRUCTIONS IN THIS SECTION ON VENTING MUST BE FOLLOWED
TO AVOID CHOKED COMBUSTION OR RECIRCULATION OF FLUE GASES.
SUCH CONDITIONS CAUSE SOOTING OR RISKS OF FIRE AND
ASPHYXIATION.
Heater must be protected from freezing downdrafts.
Remove all soot or other obstructions from the chimney that will retard a
free draft.
Type B venting is recommended with these heaters.
This water heater must be vented in compliance with all local codes, the
latest edition of the National Fuel Gas Code, ANSI Z223.1/NFPA 54, and
with the Category I Venting Tables.
In Canada, venting shall conform to the requirements of the current CAN/
CGA B149.1-00 installation code.
If any part of the vent system are exposed to ambient temperatures below
35 degrees F (2 degrees C) it must be insulated to prevent condensation.
• Do not connect the heater to a common vent or chimney with solid fuel
burning equipment. This practice is prohibited by many local building
codes as is the practice of venting gas fired equipment to the duct
work of ventilation systems.
• Where a separate vent connection is not available and the vent pipe
from the heater must be connected to a common vent with an oil burning
furnace, the vent pipe should enter the smaller common vent or chimney
at a point above the large vent pipe.
SINGLE TEMPERATURE
CIRCULATING RETURN LINE CONNECTIONS
TEMPERED WATER LOOP, IF USED, CONNECT TO POINT "A".
STORED TEMPERATURE WATER LOOP, IF USED, CONNECT TO
COLD WATER INLET

VENTING

WARNING
MIXING VALVE APPLICATION FOR TWO TEMPERATURE WATER
WARNING
TEMPERATURE SETTING SHOULD NOT EXCEED SAFE
USE TEMPERATURE AT FIXTURES. SEE TEMPERATURE
REGULATION ON PAGE 11. IF HIGHER PREHEAT
TEMPERATURES ARE NECESSARY TO OBTAIN
ADEQUATE BOOSTER OUTPUT, ADD AN ANTI-SCALD
VALVE FOR HOT WATER SUPPLIED TO FIXTURES.
VENT CONNECTION
Vent connections must be made to an adequate stack or chimney. Size
and install proper size vent pipe. Do not reduce pipe size to less than that
of the blower outlet.
Horizontal runs of vent pipe must have a minimum upward slope toward
the chimney of 1/4 inch per foot (2cm per meter). Dampers or other
obstructions must not be installed in between the heater and the blower.
Be sure that the vent pipe does not extend beyond the inside wall of the
chimney.
Where a continuous or intermittent back draft is found to exist, the cause
must be determined and corrected. A special vent cap may be required. If
the back draft cannot be corrected by the normal methods or if a suitable
draft cannot be obtained, a blower type flue gas exhauster must be employed
to assure proper venting and correct combustion.
CAUTION: IF BUILDING COLD WATER SUPPLY HAS A BACK-FLOW
PREVENTER, CHECK VALVE OR WATER METER WITH CHECK
VALVE, PROVISIONS FOR THERMAL EXPANSION OF WATER IN
THE HOT WATER SYSTEM MUST BE PROVIDED.
FIGURE 3
6
FIGURE 2
VACUUM RELIEF
VALVE
*INSTALL PER
LOCAL CODES.