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.
WARNING
DO NOT INSTALL THIS WATER HEATER DIRECTLY ON A CAR- PETED FLOOR. A FIRE HAZARD MAY RESULT. Instead the wa- 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
.
FIGURE 2
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.
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.
GAS CONNECTIONS
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. If overpressure has occurred such as through 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. The dirt leg must be 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.
DISCONNECTTHE 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.
