Operating Guide

8 • Residen al Electric Water Heater Use and Care Guide
BACKGROUND: Water expands when
heated, and the increased volume
of water must have a place to go, or
thermal expansion will cause large
increases in water pressure (despite
the use of a Pressure Reducing Valve
on the home’s main water supply
line). The Safe Drinking Water Act of
1974 requires the use of backfl ow
preventers and check valves to restrict
water from your home reentering
the public water system. Backfl ow
preventers are o en installed in water
meters and may not be readily visible.
As a result, most all plumbing systems
today are now “closed,” and almost all
homes now need a Thermal Expan-
sion Tank.
A Thermal Expansion Tank is a prac -
cal and inexpensive way to help avoid
damage to the water heater, washing
machine, dishwasher, ice maker and
even toilet valves. If your toilet oc-
casionally runs for no apparent reason
(usually briefl y at night), that may be
due to thermal expansion increasing
the water pressure temporarily.
Water pipe and tank
leaks
Leaks from plumbing pipes or from
the water heater itself can damage
property and could cause a fi re risk.
• Install an automatic leak detection
and shutoff device (available at
Lowe’s® ). These devices can detect
water leaks and can shut off the
water heater’s water supply if a
leak occurs.
Figure 6 - A suitable drain pan piped to an
adequate drain can help protect flooring
from leaks and drips.
• Install a suitable drain pan (avail-
able at Lowe’s® ) under the water
heater (Figure 6) to catch condensa-
tion or leaks in the piping connec-
tions or tank. Most codes require,
and we recommend, installing the
water heater in a drain pan that is
piped to an adequate drain. The
drain pan must be at least two inch-
es wider than the diameter of the
water heater. Install the drain pan
so the water level would be limited
to a maximum depth of 1-3/4”.
✓
Water tempera-
ture regula on
Figure 7 - Thermostatic Mixing Valves
installed at each point -of-use can help
prevent scalds.
Install Thermosta c Mixing Valves
(Figure 7) to regulate the temperature
of the water supplied to each point-
of-use (for example, kitchen sink,
bathroom sink, bath, shower). Con-
sult the valve manufacturer’s instruc-
 ons or a qualifi ed person.
WARNING! Even if the water heater
thermostat is set to a rela vely low
temperature, hot water can scald.
Install Thermosta c Mixing Valves at
each point-of-use to reduce the risk of
scalding (page 4).
BACKGROUND: A Thermosta c Mix-
ing Valve, installed at each point-
of-use, mixes hot water from the
water heater with cold water to more
precisely regulate the temperature of
hot water supplied to fi xtures. If you
aren’t sure if your plumbing system
is equipped with properly installed
and adjusted Thermosta c Mixing
Valves at each point where hot water
is used, contact a qualifi ed person for
more informa on.
INSTALLATION
INSTALLATION