WARNING! Working near an
energized circuit can result in severe
injury or death from electrical shock.
WARNING! When you are finished,
be sure all covers are secured to
reduce the risk of fire and electric
shock.
No Hot Water
The most likely reasons for an electric
water heater to produce NO hot water
are:
• No electric power—a common
problem with new installations.
• Burned out upper element (Dry Fired)
— a common problem with new
installations.
• Tripped Energy Cut Off (red button on
upper thermostat).
• The water heater’s inlet and outlet
connections are reversed (usually only
in new installations).
• Broken upper thermostat (or wiring).
• A leak in the hot water side of the
plumbing system that exceeds the
water heater’s heating capacity and
makes it appear that the water heater
is producing little to no hot water.
Follow these steps to diagnose and
correct common electrical problems:
1
Check the electric power to
the water heater.
No hot
water is often caused by a
problem with the electrical wiring or
circuit breakers. You’ll need a non-con
-
tact circuit tester. Follow these
guidelines:
• Locate the water heater’s circuit
breaker and turn it off (or remove the
circuit’s fuses).
• Open the electrical junction box.
• Identify the two power wires. The
power wires are usually black/black or
black/red—the green or copper wire
is the ground wire.
Figure 21 -
Use a non-contact circuit tester to
check for electrical power.
• Turn the circuit breaker back on (or
install the fuses) and check the power
on both incoming power wires using a
non-contact circuit tester.
• Turn the power off and close the
electrical junction box.
If the water heater is not getting power,
contact a qualified person to have the
wiring or circuit breakers checked.
2
Check the upper heating
element.
If the water heater is
getting electrical power, check
to see if the upper heating element has
burned out. If the upper element is
burned out, you’ll have no hot water. To
check the upper element, you’ll need a
multimeter capable of reading
resistance.
• Turn the power OFF at the circuit
breaker or remove fuses.
• Open the electrical junction box.
• Remove the insulation to access
the upper thermostat and heating
element.
3
Check the top two screws of
the upper thermostat using a
non-contact circuit tester and
confirm that power is off
(
screw
terminals 1 and 3 in photo on next
page).
• With the electrical power off, remove
the two power wires from the upper
heating element.
Figure 22 -
Use a multimeter to check the
resistance of the upper heating element.
4
Check the resistance of the
upper heating element using a
multimeter.
Measure the
resistance between the two screw
terminals on the upper heating
element. A good element will have a
resistance between 5 and 25 Ohms. If
the resistance is:
Outside this range.
Replace the
element (see the Routine Maintenance
section on page 25). On a new water
heater, a burned out upper heating
element is almost always caused by
turning the power on before the tank
was completely full of water (Dry Fire).
(See Step 8 in the Installation section.)
Within this range.
Reattach the power
wires, making sure the wires are in
good condition and the connections
are clean and tight. Next, check the
following:
Commercial Electric Water Heater Use and Care Guide • 21
TROUBLESHOOTING
TR
OUBLE
SHOO
TING
