Installation Guide
Residen al Standard Gas Water Heater Use and Care Guide • 15
INSTALLATION
Residen al Standard Gas Water Heater Use and Care Guide • 15
INSTALLATION
requires the use of backfl ow preven-
ters 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 Expansion 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
Figure 14 - A metal drain pan piped to an ad-
equate drain can help protect flooring from leaks 
and drips.
Leaks from plumbing pipes or from the 
water heater itself can damage prop-
erty and could cause a fi re risk.
• Install an automa c leak detec on 
and shutoff  device ( available from 
Lowe’s®). These devices can detect 
water leaks and can shut off  the 
water heater’s water supply if a leak 
occurs.
• Install a metal drain pan (available-
  from Lowe’s® ) under the water heat-
er to catch condensa on or leaks 
from the piping connec ons or tank. 
Most codes require, and we recom-
mend, installing the water heater in 
a metal drain pan that is piped to an 
adequate drain. The drain pan must 
be at least two inches 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”. The pan must not 
restrict air fl ow to the burner.
✓
Water Tempera-
ture Regula on
Install Thermosta c Mixing Valves to 
regulate the temperature of the water 
supplied to each point-of-use (for 
example, kitchen sink, bathroom sink, 
bath, shower). Install and adjust the 
mixing valve according to its manufac-
turer’s instruc ons.
WARNING! Even if the water 
heater’s 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.
Figure 15 - Thermostatic Mixing Valves installed 
at each point-of-use can help avoid scalding
BACKGROUND: A Thermosta c Mixing 
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.










