Mechanical Venting; Water Heater Installation; Water Line Connections; T&P Valve Discharge Pipe - AO Smith BTR120 Manuel D'instructions

MECHANICAL VENTING

SINGLE UNIT INSTALLATION
When mechanical venting of these heaters is desired, the
following kits are available.
Models 120 through the 200/A
A. O. Smith part number 9005381205
Models 250/A through the 400/A
A. O. Smith part number 9003434205
Where an approved power venter is to be installed to operate
in conjunction with the water heater thermostat, the following
codes must be adhered to. Field wiring should conform to
the current edition of the National Electrical Code NFPA 70.
For Canadian installations the electrical connections and
grounding shall be done in accordance with the current edition
of the Canadian Electrical Code CSA C22.1 and/or local codes.

WATER LINE CONNECTIONS

The water piping installation must conform to these instructions
and to all local code authority having jurisdiction. Good practice
requires that all heavy piping be supported.
Read and observe all requirements in the following sections
before installation of the water piping begins:
1. Water Temperature Control and Mixing Valves on page 13.
2. Dishwashing Machines on page 14.
3. Temperature-Pressure Relief Valve on page 14-15.
4. Closed Systems and Thermal Expansion on page 14.
5. For multiple water heater installations see Water Piping
Diagrams beginning on page 40.
WATER (POTABLE) HEATING AND SPACE HEATING
1. All piping components connected to this unit for space
heating applications shall be suitable for use with potable
water.
2. Toxic chemicals, such as those used for boiler treatment,
shall NEVER be introduced into this system.
3. This unit may NEVER be connected to any existing heating
system or component(s) previously used with a non-potable
water heating appliance.
4. When the system requires water for space heating at
temperatures higher than required for domestic water
purposes, a tempering valve must be installed. Please
refer to installation diagrams beginning on page 40 of this
manual for suggested piping arrangements.
5. These water heaters cannot be used in space heating
applications only
THERMOMETERS (NOT SUPPLIED)
Thermometers should be obtained and field installed as shown
in the installation diagrams.
Thermometers are installed in the system as a means of
detecting the temperature of the outlet water supply.

WATER HEATER INSTALLATION

VENT INSTALLATION
Seal all joints between the power venter and the vent
termination. This is to prevent leakage of exhaust products
into the room(s) due to positive pressure of blower.
The "Sequence of Operation" description will be the same with
mechanical venting except;
When the water heater thermostat calls for heat:
Thermostat contacts "Close" and the power venter blower
(120 VAC) is energized. Sufficient draft must be established
for the "Draft Prover Switch (N.O.)" to "Close". When the
draft prover switch "Closes" the relay coil of the flue damper
is energized.
MULTIPLE UNIT INSTALLATION
For multiple unit installations, contact A. O. Smith, Technical
Support Center at 1-800-527-1953.
WATER PIPING DIAGRAMS
This manual provides detailed water piping diagrams for typical
methods of application for the water heaters, see Water Piping
Diagrams beginning on page 40.
The water heater may be installed by itself, or with a separate
storage tank. When used with a separate storage tank, the
circulation may be either by gravity or by means of circulating
pump. Adjust flow by throttling a full port ball valve installed in the
circulating line on the outlet side of the pump. Never throttle flow
on the suction side of a pump. See the Water Piping Diagrams
beginning on page 40.
NOTE: In addition to the factory installed Temperature-Pressure
Relief Valve (T&P valve) on the water heater, each remote
storage tank that may be installed and piped to a water heating
appliance must also have its own properly sized, rated and
approved Temperature-Pressure Relief Valve installed.
Call the toll free technical support phone number listed on the
back cover of this manual for further assistance in sizing a T&P
valve for remote storage tanks.
T&P VALVE DISCHARGE PIPE
21
Explosion Hazard
Temperature-Pressure Relief Valve
must comply with ANSI Z21.22-
CSA 4.4 and ASME code.
Properly sized temperature-
pressure relief valve must be
installed in opening provided.
Can result in overheating and
excessive tank pressure.
Can cause serious injury or death.