6
Installing the water heater
Thermal Expansion
Determine if a check valve exists in the inlet water line.
It may have been installed in the cold water line as a separate back flow preventer, or it may be part of a pressure reducing valve, water meter or water softener. A check valve located in the cold water inlet line can cause what is referred to as a “closed water system.”
A cold water inlet line with no check valve or back flow prevention device is referred to as an
“open” water system.
As water is heated, it expands in volume and creates an increase in pressure within the water system. This action is referred to as “thermal expansion.” In an “open” water system, expanding water which exceeds the capacity of the water heater flows back into the city main where the pressure is easily dissipated.
A “closed water system,” however, prevents the expanding water from flowing back into the main supply line, and the result of “thermal expansion” can create a rapid and dangerous pressure increase in the water heater and the system piping. This rapid pressure increase can quickly reach the safety setting of the relief valve, causing it to operate during each heating cycle. Thermal expansion, and the resulting rapid and repeated expansion and contraction of components in the water heater and piping system can cause premature failure of the relief valve, and possibly the heater itself. Replacing the relief valve will not correct the problem.
The suggested method of controlling thermal expansion is to install an expansion tank in the cold water line between the water heater and the check valve. The expansion tank is designed with an air cushion built in that compresses as the system pressure increases, thereby relieving the over pressure condition and eliminating the repeated operation of the relief valve. Other methods of controlling thermal expansion are also available. Contact your installing contractor, water supplier, or plumbing inspector for additional information regarding this subject.
NOTICE: DO NOT apply heat to the HOT or COLD water connections. If sweat connections are used, sweat tubing to adapter before fitting adapter to the water connections on heater. Any heat applied to the water supply fittings will permanently damage the dip tube and/or heat traps.
Water Supply Connections
Refer to the illustrations below and on the next page for suggested typical installation.
The installation of unions or flexible copper connectors is recommended on the hot and cold water connections so that the water heater may be easily disconnected for servicing if necessary. The HOT and COLD water connections are clearly marked and are 3/4" NPT on all models. Install a shut-off valve in the cold water line near the water heater. Local codes may require an antisiphon device on the water inlet of a side connect water heater.
Temperature & Pressure
Relief Valve Coupling
Hot Water
Outlet Coupling
Anode Location
FRONT OF WATER HEATER
Cold Water
Inlet Coupling
Electrical
Junction
Bracket
A new combination temperature and pressure relief valve, complying with the Standard for Relief
Valves and Automatic Gas Shut-Off Devices for Hot Water Supply Systems, ANSI Z21.22, is supplied and must be installed in the opening provided and marked for the purpose on the water heater. No valve of any type should be installed between the relief valve and the tank. Local codes shall govern the installation of relief valves.
Typical Installation
WARNING: The pressure rating of the relief valve must not exceed 150 PSI, the maximum working pressure of the water heater as marked on the rating plate.
To Electrical
Distribution Panel
Flexible Connectors for
Water Connections at
Tank Fittings
Shut-Off Valve in
Cold Water
Supply Line
Grounding Screw
Wiring Junction
Bracket
Temperature & Pressure
Relief Valve
Anode
(Pictured from rear of heater with Top Panel and Insulation Pad removed).
To Cold Water
Supply
To Electrical Distribution
Panel
(Use only Copper Conductors)
Relief Valve Discharge
Line to suitable open drain
Hot Water
Outlet to Fixtures
Relief Valve
The Btuh rating of the relief valve must not be less than the input rating of the water heater as indicated on the rating label located on the front of the heater
(1 watt=3.412 Btuh).
Connect the outlet of the relief valve to a suitable open drain so that the discharge water cannot contact live electrical parts or persons and to eliminate potential water damage.
Piping used should be of a type approved for hot water distribution. The discharge line must be no smaller than the outlet of the valve and must pitch downward from the valve to allow complete drainage (by gravity) of the relief valve and discharge line. The end of the discharge line should not be threaded or concealed and should be protected from freezing. No valve of any type, restriction or reducer coupling should be installed in the discharge line.
7
8
Installing the water heater
To Fill the Water Heater
WARNING: The tank must be full of water before heater is turned on. The water heater warranty does not cover damage or failure resulting from operation with an empty or partially empty tank.
Make certain the drain valve is completely closed.
Open the shut-off valve in the cold water supply line.
Open each hot water faucet slowly to allow the air to vent from the water heater and piping.
A steady flow of water from the hot water faucet(s) indicates a full water heater.
CAUTION: The presence of water in the piping and water heater does not provide sufficient conduction for a ground. Non-metallic piping, dielectric unions, flexible connectors etc. can cause the water heater to be electrically isolated.
Condensation
Condensation can form on the tank when it is first filled with water. Condensation might also occur with a heavy water draw and very cold inlet water temperature.
This condition is not unusual, and will disappear after the water becomes heated.
If, however, the condensation continues, examine the piping and fittings for possible leaks.
Electrical Connections
A separate branch circuit with copper conductors, overcurrent protective device and suitable disconnecting means must be provided by a qualified electrician.
All wiring must conform to local codes or latest edition of National Electrical Code
ANSI/NFPA 70.
The water heater is completely wired to the junction box inside jacket at the top front of the water heater. An opening for
1/2″ or 3/4″ electrical fitting is provided for field wiring connections.
The voltage requirements and wattage load for the water heater are specified on the rating plate on the back of the water heater.
The branch circuit wiring should include either:
Metallic conduit or metallic sheathed cable approved for use as a grounding conductor and installed with fittings approved for the purpose.
Non-metallic sheathed cable, metallic conduit or metallic sheathed cable not approved for use as a ground conductor shall include a separate conductor for grounding. It should be attached to the ground terminals of the water heater and the electrical distribution box.
