Installation Guide

18 • Residen al Electric Water Heater Use and Care Guide
INSTALLATION
18 • Residen al Electric Water Heater Use and Care Guide
INSTALLATION
The Electronic Thermostat
IMPORTANT: The Energy Smart® Mod-
ule (ESM) must be removed before
a emp ng to access the thermostat.
NOTE: For the Electronic Thermostat
(ET) changes to remain in eff ect the
Energy Smart® Module (ESM) must
not be reconnected, also read the
“Water Temperature Regula on”
under the “Opera ng Your Water
Heater” sec on. If the instruc ons are
not clear, contact a qualifi ed service
technician.
The Energy Smart® Module (ESM)
is intended to serve as the primary
interface for opera ng the water heat-
er; however, the Electronic Thermo-
stat (ET) may control the water heater
in the absence of the Energy Smart®
Module (ESM).
The Electronic Thermostat consists of
an electronics box that contains a low
voltage power supply, the thermo-
stat set point knob, relays to switch
between the upper and lower hea ng
elements, one control thermistor,
a connector for the lower element
control thermistor, microelectronics
to convert the thermistor signals and
perform switching and other logic
func ons, and a connector to  e the
Electronic Thermostat (ET) to the En-
ergy Smart® Module (ESM) located on
the front of the water heater jacket.
The majority of the self-diagnos cs
are located in the Electronic Thermo-
stat (ET), including the dry-fi re protec-
 on intelligence. The thermostat
circuit is designed so that when the
upper hea ng element calls for heat,
the power is directed to that element
even if the lower element is also call-
ing for heat.
Diagnos c LED Light
The Green/Red LED light indicates the
status of the electronic thermostat
(See Figure 22).
WARNING! Electrical Shock Hazard
Do not remove the plas c guard from
over wiring.
Do not touch electrical wiring.
Failure to do so can result in death or
electrical shock.
Electronic Thermostat (ET)
Diagnostic
LED Light
ECO
Reset
Button
Setpoint
Knob
Remove Only After Power Is
Turned Off When Replacing Element.
Plastic Guard
Upper
Element
Figure 22 - Electronic Thermostat
• Green LED will signal normal
opera on. The green LED will
blink 2  mes per second to indi-
cate that power is applied to the
upper hea ng element and at a
faster rate (4  mes per second)
to indicate that the lower hea ng
element is powered.
• Red LED will fl ash error codes. If
a fault is detected by the elec-
tronic thermostat, the LED light
indicator will use the red LED to
indicate the fault detected. The
fl ash code sequence is to consist
of 1/2 second fl ashes of the red
LED each separated by a 1/2 sec-
ond off period.
The number of fl ashes indicates the
fault code number.
(See diagnos c code chart sec on in
this manual, page 22).
A er the last 1/2 second “on” period,
the LED will remain off un l a total of
5 seconds has elapsed for the fault
indica on cycle (there is a 5 seconds
delay before the fault fl ash pa ern
repeats). A er the 5 seconds are
completed, the fault indica on cycle
is repeated star ng with the fi rst 1/2
second-fl ash. The fl ash sequence will
be repeated as long as the fault re-
mains. Only one fault can be declared
at a  me. NOTE: the green LED is
turned off when a fault code is being
displayed, even though the heater
may be opera ng in limp mode with
an element on. See diagnos c code
chart sec on in this manual.
Overriding The Energy Smart®
Module (ESM)
If the Energy Smart® Module (ESM)
is not working, simply unplug the
interface module and turn the set
point knob on the Electronic Thermo-
stat (ET) to the desired temperature
(See Figure 22). To replace a broken or
damaged ESM module, see page 32
for ordering informa on.
NOTE: Disconnec ng the ESM will
disable the leak detec on sensor.
WARNING! Electrical Shock Hazard
Do not remove the plas c guard from
over wiring.
Do not touch electrical wiring.
Failure to do so can result in death or
electrical shock.
Energy Smart
®
Module (ESM)
Electronic
Thermostat (ET)
Thermostat
Setpoint Knob
Junction Box
Wiring Harness
Thermistor
Wire Harness
Figure 23 - Energy Smart® Module
NOTE: Smart Grid will be disabled
when the Energy Smart® Module
(ESM) is disconnected from the junc-
 on box wiring harness.