INLET AND OUTLET CONNECTIONS
For ease of service, install unions on the cold water inlet and hot water outlet of the water heater. The cold water inlet connection is located on the lower left front side of the water heater. A manual shutoff valve should be installed upstream on the cold water source as an isolation device. The hot water outlet connection is located on the top center of the water heater. A manual shutoff valve should be installed downstream on the hot water outlet source as an isolation device in case the water heater must be disconnected from the system.
STORAGE TANK
This appliance uses a glass lined steel storage tank to store the heated water for use. The storage tank is constructed in accordance with the requirements of the Underwriters Laboratory Listing for a commercial electric water heater. The tank is furnished with threaded connections for cold water inlet, hot water outlet, a relief valve and a drain connection. The storage tank has a hand hole for ease of inspection, cleanout and service. The interior of the storage tank is glass lined and fired to 1600˚F (871˚C) to insure a molecular fusing of glass and steel to protect the steel base metal against corrosion. A magnesium anode is standard to help prevent dissipation of the tank material by electrolytic action.
RELIEF VALVE
This water heater is supplied with a temperature and pressure relief valve(s) sized in accordance with ASME Boiler and Pressure Vessel Code, Section IV. Some water heaters may be supplied with an optional pressure only relief valve. The relief valve(s) is installed in the vertical position and mounted in the tapping provided in the storage tank. No valve is to be placed between the relief valve, and the water heater. To prevent water damage, the discharge from the relief valve must be piped to a suitable floor drain for disposal when relief occurs. No reducing couplings or other restrictions shall be installed in the discharge line. The discharge line shall allow complete drainage of the valve and line. Relief valves should be manually operated at least once a year. A relief valve that fails to completely reseat and continues to discharge water must be immediately replaced with a new, properly sized, temperature and pressure relief valve.
CAUTION
Avoid contact with hot discharge water. Insure that no one is in front of or around the relief valve discharge line. Make sure that the extremely hot water manually discharged from the relief valve will not cause bodily injury or property damage.
THERMAL EXPANSION
OF WATER
A relief valve that discharges periodically may be due to thermal expansion in a closed system. Many water systems are equipped with pressure reducing valves, check valves or back flow preventers which may cause the water system to be closed. As water is heated it will expand in volume due to thermal expansion. The system must make allowance for this expansion. If an expansion tank is not provided in the system, water pressure may increase to the point where the water heater's temperature and pressure relief valve opens to relieve the excess pressure. The temperature and pressure relief valve is not intended for the constant relief of thermal expansion. This is an unacceptable condition and must be corrected. Do not plug or cap the relief valve discharge! A properly sized expansion tank is typically installed in the potable water system to relieve the pressure built up by thermal expansion of heated water. Consult your local plumbing contractor and plumbing wholesaler for assistance in properly selecting an expansion tank for your system.
As the water heater operates, there may be noises generated by the expansion and contraction of the metal parts of the water heater and related piping. These noises may occur during periods of heat up or cool down. They do not represent harmful or dangerous conditions.
CATHODIC PROTECTION
Hydrogen gas can be produced in a hot water system that has not been used for a long period of time (generally two weeks or more). Hydrogen gas is extremely flammable. To prevent the possibility of injury under these conditions, we recommend the hot water faucet be open for several minutes at a sink close to the water heater before you use any electrical appliance which is connected to the hot water system. If hydrogen is present, there will be an unusual sound such as air escaping through the pipe as the hot water begins to flow. There should be no smoking or open flames near the faucet at the time it is open.
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