Can be
used as
120v by
bypassing
screws on
right side
Standard 120v
single element
Standard 240v
single element
Standard 120v
single element
Standard 240v
single element
Therm-O-Disc Style
10
11
Element Testing
Be sure the power is off. Disconnect the two wires
from the element. Attach or touch the clip to one of
the element terminals and the tester probe to the other
element contact. The tester diode light should glow.
Touch the probe to the metal on the element flange.
The diode should
NOT
glow. Now attach the clip to
the other terminal and touch the probe to the element
flange. The diode should
NOT
glow.
If any or all of these three tests fail, replace the element.
Lower Thermostat Testing
Be sure the power is off. Disconnect wires from the
lower element terminals. Touch the clip and the probe
to terminals on the lower thermostat. If the water in the
tank is colder than the thermostat setting – thermostat
calling for heat – the diode will glow. If not, replace the
thermostat. If the water is hot, turn the setting higher and
perform the test.
Be sure to return the setting back to the proper setting.
Upper Thermostat Testing
Be sure the power is off. Disconnect wires from the
upper element terminals. Touch the clip and the probe to
terminals 1 and 2 on the thermostat. (See diagram.) If the
water in the tank is cold – thermostat calling for heat – the
diode should glow. If not, replace the thermostat. If the
tank is hot, turn the thermostat setting to a higher setting
and perform the test.
Be sure to return the thermostat to the proper setting if
the thermostat is not replaced.
Single Element Thermostat
The test is the same as the one for the lower thermostat
(above). Use terminals 1 and 2 on the thermostat.
Most of the smaller water heaters and point-of-use heaters
are designed with only one element and thus only one
thermostat. Most of the single element water heaters are
wired for 120v. Never connect or adapt a 120v water heater
to a 240v system.
Because there is no “upper” thermostat on this type heater,
the high limit control is attached to the only or lower
thermostat. (See diagrams for proper wiring.)
Single Element Thermostat Wiring
(with high limit)
NOTE: Because the HLC is attached to the single
element thermostat, it looks similar to an upper
thermostat for a two-element heater. Care should
be taken in choosing the correct replacement
thermostat. An upper thermostat will not work on
a single element heater.
High limit
control
for Single element heater
for Single element heater
Apcom Style
Testing Elements and Thermostats
for Failure
Camco’s Water Heater Tester (#10023) is designed specifically for use on electric water heaters. The
elements and thermostats are tested while installed on the heater. The tester’s specially engineered
light emitting diode will identify filament connections that other testers routinely miss.
Never use this tester on live electrical circuits. Electricity must be turned off at the power source.
The tester comes with 2 AAA batteries installed. To test the batteries, touch the alligator clip to the test
probe. The diode should glow.
Summary of Contents for Residential Electric water heater
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