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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 softerner. 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 the 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 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 addition 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 on pages 8 and
9 for suggested typical installations. 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.
CAUTION: SIDE CONNECT MODELS are equipped with a special Hot Outlet Tube
Assembly. DO NOT rotate the Hot Outlet
Nipple when making water connections. The nipple MUST remain in a position with the indicating mark facing up.
A new combination temperature and pressure relief valve, complying with the Standard for Relief
Valves 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.
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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.
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.
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WARNING: DO NOT turn on the electrical supply or operate this water heater unless it is completely full of water.
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.
To Fill the Water Heater
Make certain the drain valve on the water heater 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.
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.
7
8
Installing the water heater.
Typical Side Connect Installation
Anode
Electrical junction box
(use only copper conductors)
Temperature & pressure relief valve
Union
Hot water outlet to fixtures
Union
To cold water supply
Relief valve discharge line.
Directed to under side of home.
Typical Top Connect Installation
Anode
Temperature & pressure relief valve
Electrical junction box
(use only copper conductors)
Union
Heat trap
6 ″ Min.
Hot water outlet to fixtures
Relief valve discharge line.
Directed to under side of home.
To electrical distribution panel
Jacket access panel
Shut-off valve
Jacket access panel
Drain valve
Auxiliary catch pan
Heat trap
6 ″ Min.
To electrical distribution panel
To cold water supply
Shut-off valve
Union
Jacket access panel
Jacket access panel
Drain valve
Auxiliary catch pan
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Key Features
- Designed for manufactured housing
- Can be connected for side or top water connections
- Has both single and double element models
- Is efficient
- Has safety controls
- Has adjustable water temperature