Part 3 - Piping; Plumbing; Thermal Expansion; Condensation - Westinghouse WEC080C2X030 Use And Care Manual

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Part 3 - Piping

A. Plumbing
It is mandatory that all plumbing be done in accordance with
federal, local, and state plumbing codes and practices. Failure
to properly install the water heater WILL VOID the warranty.
It is also necessary to use both thread tape and pipe sealing
compound on all mechanical plumbing connections.
It is recommended to use unions on the hot and cold water
connections to easily disconnect the water heater for servicing.
Dielectric unions or galvanized steel fittings must not be used
in a system with this water heater. Doing so WILL VOID the
warranty. It is recommended to use only copper, brass, or
stainless steel fittings. Teflon thread sealant must be used on
all connections.
1. Install a shut-off or check valve or both on the inlet connection
on the top of the heater. Connect the cold water supply line to
the shut-off valve or check valve. Refer to piping Applications,
this manual.
Do not apply heat to the Hot or Cold water heater connections. If
sweat connections are used, sweat tubing to the adapter before
fitting adapter to the water connections on the heater. Any
heat applied to the water heater connections will permanently
damage the dip tube and/or heat traps. Damages due to
improper installation practices ARE NOT covered by warranty.
2. Connect the hot water line to the connection marked "HOT"
on the top of the water heater.
3. Install the T&P Valve in the opening provided near the top of
the heater.
4. Install drain valve in the opening provided near the bottom of
the heater.
B. Thermal Expansion
A check valve may be installed in the cold water inlet line as
a separate backflow preventer, or may be part of a pressure
reducing valve, water meter, or water softener. An "open water
system" refers to a system without a check valve. A "closed
water system" refers to a system with a check valve installed in
the cold water inlet line.
As water is heated, it expands in volume and increases 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 system flows back into the city main
where pressure is easily dissipated.
A closed water system prevents expanding water from flowing
back to the city main. The resulting thermal expansion can rapidly
increase pressure in the water heater and system piping. This
rapid pressure increase can exceed the setting of the pressure
relief valve, causing it to operate during each heating cycle,
resulting in discharge from the T&P. This rapid and repeated
expansion and contraction of components in the system can
cause premature failure of system components, including the
relief valve and possibly the water heater. Replacing the relief
valve will not correct thermal expansion.
A potable hot water expansion tank is required to offset thermal
whl-035 Rev. 4.5.16
expansion. Expansion tanks are designed with an air cushion
built in that compresses as system pressure increases, thereby
relieving the overpressure condition and eliminating repeated
operation of the relief valve. This expansion tank should be
installed in the cold water line between the water heater and
check valve, and must be sized for the entire water volume of
the hot water system. See piping Applications.
Other methods of controlling thermal expansion are
available. Check with the local water utility to determine if
a check valve exists in the cold water inlet line. Contact your
installing contractor, water supplier, or plumbing inspector for
additional information regarding thermal expansion.
C. Condensation
Condensation can form on the water heater when it is first
filled with water, and may also occur with a heavy water draw
and very cold inlet water temperature. This condition is not
unusual and will disappear as the water becomes heated.
However, if the condensation should continue, examine the
piping and fittings for possible leaks.
D. Insulation Blankets
If local codes require external application of insulation blanket
kits, the manufacturer's instructions included with the kit
must be carefully followed.
In addition, pay careful attention to the following so as not
to restrict the proper function and operation of the water
heater:
• Do not cover the operating or warning labels attached
to the water heater or attempt to locate them on the
exterior of the insulation blanket.
• Do not apply insulation to the top of the water heater.
This could interfere with the safe operation of the
electrical junction box.
• Do not cover the jacket access panel(s) to the
thermostat(s) and heating element(s) or T&P valve.
• Inspect the insulation blanket frequently.
Failure to follow these instructions could result in property
damage, severe personal injury, or death.
E. Temperature and Pressure Relief Valve
For protection against excessive pressures and temperatures
in this water heater, install temperature and pressure
protective equipment as required by local codes, but not less
than a combination T&P valve meeting the requirements for
Relief Valves and Automatic Gas Shutoff Devices for Hot Water
Supply Systems, ANSI Z21.22B / CSA 4.4-M99 by a nationally
recognized testing laboratory that maintains periodic
inspection of production listed equipment and materials. This
valve must be marked with a maximum set pressure not to
exceed the marked maximum working pressure of the water
heater. Install the T&P valve into the opening provided and
marked for this purpose on the water heater. The T&P valve
must be plumbed down so discharge can exit at least 6" above
the structural floor. The relief line cannot be in contact with
any live electrical parts.