Step 6:
Install shutoff and
tempering valves
1
If one is not already installed,
install a manual shutoff valve
in the cold water line that
supplies the water heater. Install the
shutoff valve near the water heater so
that it is readily accessible. Only use
valves that are compatible with
potable water. Use only full-flow ball
or gate valves. Other types of valves
may cause excessive restriction to the
water flow.
2
Install a Thermostatic Mixing
Valve. Consult the valve
manufacturer’s instructions
or a qualified person.
Figure 14 -
Install Thermostatic Mixing Valves
where hot water will be used.
WARNING! Even if the water
heater’s thermostat(s) are set to a
relatively low temperature, hot water
can scald. Install Thermostatic Mixing
Valves to reduce the risk of scalding.
(see page 4.)
3
For water heaters that are fed
by a solar water heating
system (or any other pre-
heating system), always install a
Thermostatic Mixing Valve or other
temperature limiting device in the inlet
water supply line to limit water supply
inlet temperature to 120°F (49°C).
Solar water heating systems can supply
water with temperatures exceeding
170°F (77°C) and may result in water
heater malfunction.
WARNING! Hot water provided by
solar heating systems can cause
severe burns instantly, resulting in
severe injury or death (see page 4).
Step 7:
1
Connect the water
supply
Determine the type of water pipes in
the plumbing system. Most systems
use copper water pipes, but some
use CPVC or cross-linked polyethylene
(PEX). Use fittings appropriate for the
type of pipe in the plumbing system.
Do not use iron or PVC pipe – they are
not suitable for potable water.
2
Connect the cold water
supply using 3/4 inch (19mm)
National Pipe Thread “NPT”
to the cold water inlet nipple.
For ease of removing the water heater
for service or replacement, connect
the water pipes with a coupling
called a union. We recommend using
a dielectric-type union (available at
local plumbing supplier
). Dielectric
unions can help prevent corrosion
caused by tiny electric currents
common in copper water pipes and
can help extend the life of the water
heater.
16 • Commercial Electric Water Heater Use and Care Guide
INSTALLATION
IF YOU HAVE COPPER
PIPES:
If the plumbing system has copper
water pipes, you can solder the
water pipe connections or use
compression fittings which don’t
require soldering. Compression
fittings are easier to install than
soldering pipe. Check with local
plumbing officials to determine
what types of pipe materials are
suitable for your location. Do not
use lead-based solder.
NOTICE:
Do not solder pipes while
they are attached to the water
heater. The water heater’s inlet
and outlet connections contain
non-metallic parts which could
be damaged. The proper way
to connect the water heater to
copper water pipes is as follows:
• Solder a short length of pipe
(about a foot or so) to a
threaded adapter using only
95/5 tin-antimony or equivalent
solder. Attach the threaded
adapters to the water heater’s
connections (using thread
sealant tape or pipe joint
compound). Connect the water
pipes by soldering, keeping the
connections at the water heater
cool with wet rags.
INS
TALLA
TION
