Part 4 - Water Piping; General Plumbing Guidelines; Backflow Preventer; Potable Expansion Tank - Westinghouse WGRGH20**75F Series Installation, Start-Up, Maintenance, Parts, Warranty

Part 4 - Water Piping

Failure to follow the instructions in this section WILL VOID the
warranty and may result in property damage, severe personal
injury, or death.
DO NOT pipe this water heater with black iron, galvanized steel,
steel, or lead pipe. Doing so will result in premature product
failure and property damage, and WILL VOID the warranty.
Do not apply a torch within 12" of the water heater. If sweat
connections are used, sweat tubing to the adapter before fitting
adapter to the water connections on the heater. Damages due to
improper installation practices ARE NOT covered by warranty.
Dielectric unions or galvanized steel fittings must not be used in
a system with this water heater. Doing so WILL VOID the warranty.
Use only copper, brass, or stainless steel fittings. Teflon thread
sealant must be used on all connections.
A. General Plumbing Guidelines
Use two wrenches when tightening water piping at heater. Use
one wrench to prevent the heater return or supply line from
turning. Failure to prevent piping connections from turning could
cause damage to heater components.
The heater control module uses a temperature sensor to provide
high limit protection. Some codes / jurisdictions may require
additional external controls.
The domestic water connections must be installed in accordance
with all local and national plumbing codes, or any applicable
standard which prevails. The inlet (cold) and outlet (hot) ports are
3/4" on all models.
• Pipe material must be suitable to meet local codes and
industry standards.
• It is recommended to use brass, stainless steel, or copper
unions / nipples in the water heater system.
• When installing more than one water heater to supply higher
volumes of hot water in residential applications, the number
of water heaters required and the header pipe sizing needs
to be properly sized to meet the total hot water demand.
• The pipe must be cleaned and without blemish before any
connections are made.
• Isolation (shutoff valves) should be used to ease future
servicing.
• All water piping should be insulated.
It is recommended to install a sweat shut-off valve and a union in the
cold inlet piping and hot outlet to ease future servicing. If there is a
backflow preventer or any type of a no return valve in the system,
install an additional tee here, suitable for a potable hot water
expansion tank.
In the hot outlet, install a suitable adapter to match the tubing of
the plumbing system. A recirculation line may be installed here
to provide additional energy savings and prevent the thermal
siphoning of domestic hot water.
Ensure the cold water inlet and hot water outlet pipes are not
reversed. Doing so will cause the water heater to operate improperly
and void warranty. Ensure the hot and cold lines are connected
properly.
B. Backflow Preventer
Use a backflow preventer specifically designed for water heater
installations. This valve should be installed on the cold water fill supply
line per local codes.
C. Potable Expansion Tank
A potable hot water expansion tank is required to offset heated water
expansion. In most city plumbing systems, the water meter has a
no return or back flow device built into the system to prevent back
flowing of water into city mains. Some local codes require back flow
preventers on all incoming water supplies. The hot water expansion
tank must be listed for potable water use. The expansion tank should
be located on the cold inlet piping close to the water heater.
Expansion Tank
1. Ensure that the expansion tank is sized to correctly handle heater
and system water volume and temperature.
Undersized expansion tanks cause system water to be lost from the
relief valve, causing make-up water to be added. Eventual heater
failure can result due to excessive make-up water addition. SUCH
FAILURE IS NOT COVERED BY WARRANTY.
The expansion tank must be suitable for hot potable water systems.
2. The expansion tank must be located as shown in Applications, this
manual, or following recognized design methods. See expansion tank
manufacturer's instructions for details.
D. Piping the Water Heater
Use at least the MINIMUM pipe size for all water heater loop piping
This is to avoid the possibility of inadequate flow through the water
heater. Using less than the required minimum pipe size and piping
could result in system problems, property damage, and premature
water heater failure. Such problems ARE NOT covered by product
warranty.
Use both thread tape and pipe dope to connect to the ¾" domestic
water inlet and outlet. Tankless isolation valves between the city water
supply and tank inlet are recommended for ease of service.
Figure 8 - Installing the Water Pipes
whl-605 Rev. 002 Rel. 000 Date 1.23.19
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