A.O. Smith AOSRG45200 Owner's Manual page 5

a suitable drain pan should be installed under the heater, see fig.
1 (Y). The pan must not restrict combustion air flow. Such pans
should have a minimum length and width of at least 2 inches
greater than the diameter of the heater and should be piped to an
adequate drain. Drain pans suitable for these heaters are avail-
able from your dealer or A. O. Smith Water Products Company,
5621 W. 115th Street, Alsip, Illinois 60803.
DO NOT INSTALL THIS WATER HEATER DIRECTLY ON A CAR-
PETED FLOOR. A FIRE HAZARD MAY RESULT.
ter heater must be placed on a metal or wood panel extending be-
yond the full width and depth by at least 3 inches (76.2mm) in any
direction. If the heater is installed in a carpeted alcove or closet,
the entire floor shall be covered by the panel. Also, see the drain
requirements.
WATER CONNECTIONS
Refer to figure 1 for typical installation. A suitable pipe thread seal-
ant must be used to prevent leakage. For WATER HEATING (PO-
TABLE) and SPACE HEATING, figure 2.
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 Fig. 2 for
suggested piping arrangement.
CLOSED WATER SYSTEM
A closed system will exist if a back-flow preventer (check valve),
pressure reducing valve, or other similar device is installed in the
cold water line between the water heater and the street main (or
well). Excessive pressure may develop due to the thermal expan-
sion of heated water causing premature tank failure or intermittent
relief valve operation. This type of failure is not covered by the
limited warranty. An expansion tank may be necessary in the cold
water supply to alleviate this situation, see fig. 1. Contact the local
plumbing authority.
WARNING
Instead the wa-
FIGURE 2
If the temperature and pressure relief valve on the appliance dis-
charges periodically, this may be due to thermal expansion in a
closed water supply system. Contact the water supplier or local
plumbing inspector on how to correct situation. Do not plug the
temperature and pressure relief valve.
The minimum gas supply pressure for input adjustment is 4.5" W.C.
for natural gas (11.0" W.C. for propane).
THE HEATER IS NOT INTENDED FOR OPERATION AT HIGHER
THAN 14.0"-NATURAL, 14.0"-PROPANE WATER COLUMN (1/2
POUND PER SQUARE INCH [3.5 kPa]) SUPPLY PRESSURE. EX-
POSURE TO HIGHER GAS SUPPLY PRESSURE MAY CAUSE
DAMAGE TO THE CONTROL WHICH COULD RESULT IN FIRE
OR EXPLOSION.
improper testing of gas lines or emergency malfunction of the sup-
ply system, the control must be checked for safe operation. Make
sure that the outside vents on the supply regulators and the safety
vent valves are protected against blockage. These are parts of the
gas supply system, not the heater. Vent blockage may occur during
ice storms.
IT IS IMPORTANT TO GUARD AGAINST CONTROL FOULING
FROM CONTAMINANTS IN THE GAS WAYS. SUCH FOULING
MAY CAUSE IMPROPER OPERATION, FIRE OR EXPLOSION.
All piping must comply with local codes and ordinances or with the
National Fuel Gas Code (ANSI Z2223.1/NFPA-54) whichever ap-
plies. Copper and brass tubing and fittings (except tin lined copper
tubing) shall not be used.
REFER TO FIG. 1 FOR CONNECTION DETAILS. BEFORE
ATTACHING THE GAS LINE BE SURE THAT ALL GAS PIPE IS
CLEAN ON THE INSIDE.
TO TRAP ANY DIRT OR FOREIGN MATERIAL IN THE GAS SUP-
PLY LINE, A DIRT LEG (SOMETIMES CALLED DRIP LEG) MUST
BE INCORPORATED IN THE PIPING, FIG. 1.
readily accessible. Install in accordance with recommendations of
serving gas supplier. Refer to the latest edition of ANSI Z223.1.
.
To prevent damage, care must be taken not to apply too much torque
when attaching gas supply pipe to thermostat gas inlet. The ther-
mostat inlet has a pad for use with a backup wrench.
Apply joint compounds (pipe dope) sparingly and only to the male
threads of pipe joints. Do not apply compound to the first two threads.
Use compounds resistant to the action of liquefied petroleum gases.
Do not use teflon tape on thermostat fittings.
DISCONNECT THE APPLIANCE AND ITS INDIVIDUAL SHUT OFF
VALVE FROM THE GAS SUPPLY PIPING SYSTEM DURING ANY
SUPPLY PRESSURE TESTING EXCEEDING 1/2 PSI (3.5 kPa).
GAS SUPPLY LINE MUST BE CAPPED WHEN DISCONNECTED
FROM THE HEATER. FOR TEST PRESSURES AT 1/2 PSI (3.5
kPa) OR LESS, THE APPLIANCE NEED NOT BE DISCONNECTED,
BUT MUST BE ISOLATED FROM THE SUPPLY PRESSURE TEST
BY CLOSING THE MAIN MANUAL GAS VALVE.
5
GAS CONNECTIONS
If overpressure has occurred such as through
The dirt leg must be