whl-035 Rev. 002 Rel. 002 Date 11.1.17
8
B. Thermal Expansion
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.
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
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
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.
Part 3 - Piping
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.
