Installation Instructions

whl-590 Rev. 003 Rel. 003 Date 3.22.18
17
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 tting
adapter to the water connections on the heater. Damages due to
improper installation practices ARE NOT covered by warranty.
Dielectric unions or galvanized steel ttings must not be used in a
system with this water heater. Doing so WILL VOID the warranty. Use
only copper, brass, or stainless steel ttings. Teon 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 inlet or outlet line from turning. Failure
to prevent piping connections from turning could cause damage to
heater components.
The heater control module uses temperature sensors to provide
both high limit protection and modulating temperature control.
The control module also provides low water protection by sensing
the water level in the tank. 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), outlet (hot), and recirculation inlet
ports are 3/4” on all models.
Figure 7 - Operating Modes
t Pipe material must be suitable to meet local codes and
industry standards.
t The pipe must be cleaned and without blemish before any
connections are made.
t Isolation (shuto valves) should be used to ease future
servicing. Westinghouse oers isolation valves (Part #7850P-
090). These optional parts may be purchased separately.
t All water piping should be insulated.
It is recommended to install a sweat shut-o valve and a union in the
cold inlet piping and hot outlet to ease future servicing. If there is a
backow 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 thermal trap or heat trap loop may be installed
here to provide additional energy savings and prevent the thermal
siphoning of domestic hot water.
Operating Modes
Standard (DHW) Mode – This is the operating mode when there is
a call for hot water.
Preheat or Internal Recirculation Modes – When calls for hot water
are satised, the water heater is factory programmed to Preheat
and automatically maintain the temperature set point of the water
heater – 24 hours a day, 7 days a week. The dierential setting can be
adjusted to control the temperature set point.
Internal Recirculation Mode allows the installer to program specic
recirculation functions by day and time to circulate and heat
water more eciently - when the user most needs hot water. See
Recirculation Functions, this manual, for details.
External Recirculation Mode – This mode keeps an external
recirculation loop warm to make hot water production more
ecient and also aid in freeze protection. An external recirculation
line must be installed in order to recirculate water externally. The
installer may program specic recirculation functions by day and
time to circulate and heat water when the user most needs hot
water. See Recirculation Functions, this manual, for details.