A.O. Smith BTH 300A Water Heater User Manual


 
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OR LESS, THE APPLIANCE NEED NOT BE DISCONNECTED, BUT
MUST BE ISOLATED FROM THE SUPPLY PRESSURE TEST BY
CLOSING THE MANUAL GAS SHUTOFF VALVE.
BEFORE PLACING THE HEATER IN OPERATION, CHECK FOR
GAS LEAKAGE. USE SOAP AND WATER SOLUTION OR OTHER
MATERIAL ACCEPTABLE FOR THE PURPOSE OF LOCATING GAS
LEAKS. DO NOT USE MATCHES, CANDLES, FLAME OR OTHER
SOURCES OF IGNITION FOR THIS PURPOSE.
PURGING
Gas line purging is required with new piping or systems in which
air has entered.
CAUTION
PURGING SHOULD BE PERFORMED BY PERSONS
EXPERIENCED IN THIS TYPE OF GAS SERVICE. TO AVOID RISK
OF FIRE OR EXPLOSION, PURGE DISCHARGE MUST NOT ENTER
CONFINED AREAS OR SPACES WHERE IGNITION CAN OCCUR.
THE AREA MUST BE WELL VENTILATED AND ALL SOURCES OF
IGNITION MUST BE INACTIVATED OR REMOVED.
GAS METER SIZE - CITY GASES ONLY
Be sure that the gas meter has sufficient capacity to supply the
full rated gas input of the water heater as well as the requirements
of all other gas fired equipment supplied by the meter. If the gas
meter is too small, ask the gas company to install a larger meter
having adequate capacity.
GAS PRESSURE REGULATION
Main line gas pressure to the unit(s) should be a maximum
11.0" W.C. (2.74 Kpa) for natural gas and a maximum 14.0" W.C
(3.49 kPa) for propane gas. A minimum of 6.2" W.C. (1.54 Kpa) for
natural gas and a minimum of 11.0" W.C. (2.74 kPa) for propane gas.
The service regulator provided must be installed within 6' (183 cm)
of the unit and not closer than 3' of the unit. Install regulator
according to regulator manufacturer and local requirements.
GAS VALVES
WARNING
SHOULD OVERHEATING OCCUR OR THE GAS SUPPLY FAIL TO
SHUT OFF, TURN OFF THE MANUAL GAS CONTROL VALVE TO
THE APPLIANCE.
SYSTEM CONNECTIONS
The system installation must conform to these instructions and to
the local code authority having jurisdiction. Good practice requires
that all heavy piping be supported.
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.
RELIEF VALVE
This heater is equipped with an approved temperature and
pressure relief valve. ASME ratings cover pressure relief. CSA
ratings cover release rate with temperature actuation.
FOR SAFE OPERATION OF THE WATER HEATER, THE RELIEF
VALVE(S) MUST NOT BE REMOVED OR PLUGGED.
In addition to the appliance relief valve, each remote storage tank
which may be used in conjunction with this appliance shall also
be installed with a properly sized, rated and approved temperature
(ANSI) and pressure (ASME) relief valve(s). This relief valve shall
comply with the standard for relief valves and automatic gas shutoff
devices for hot water supply systems. ANSI Z21.22-CSA 4.4.
Your local code authority may have other specific relief valve
requirements.
WARNING
THE PURPOSE OF A RELIEF VALVE IS TO AVOID EXCESSIVE
PRESSURE OR TEMPERATURE INTO THE STEAM RANGE,
WHICH MAY CAUSE SCALDING AT FIXTURES, TANK EXPLOSION,
SYSTEM OR HEATER DAMAGE. NO VALVE IS TO BE PLACED
BETWEEN THE RELIEF VALVE AND THE TANK.
A DRAIN LINE MUST BE CONNECTED TO THE RELIEF VALVE TO
DIRECT DISCHARGE TO A SAFE LOCATION TO AVOID SCALDING
OR WATER DAMAGE. THIS LINE MUST NOT BE REDUCED FROM
THE SIZE OF THE VALVE OUTLET AND MUST NOT CONTAIN
VALVES OR RESTRICTIONS, NOR SHOULD IT BE LOCATED IN
FREEZING AREAS. DO NOT THREAD OR CAP THE END OF THIS
LINE. RESTRICTED OR BLOCKED DISCHARGE WILL DEFEAT
THE PURPOSE OF THE VALVE AND IS UNSAFE. THE DISCHARGE
LINE SHALL BE INSTALLED TO ALLOW COMPLETE DRAINAGE
OF BOTH THE VALVE AND LINE.
WATER LINE CONNECTIONS
This manual provides detailed installation diagrams (see back
section of this manual) for typical methods of application for the
water heaters.
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.
When a circulating pump is used, it is important to note that the
flow rate should be slow so that there will be a minimum of
turbulence inside the heater.
CLOSED SYSTEM
CAUTION
A closed system will exist if a check valve (without bypass),
pressure reducing valve (without bypass), or a water meter (without
bypass) is installed in the cold water line between the water heater
and street main (or well).
Excessive pressure may develop causing premature tank failure
or intermittent relief valve operation. This type of failure is not
covered by the limited warranty. An expansion tank or a similar
device may be required in the inlet supply line between the
appliance and the meter or valve to compensate for the thermal
expansion of water under supply pressure.
If a water heater is installed in a closed water system, check local
codes or contact the water supplier or local plumbing inspector on
how to control this situation.
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.