Installation Guide & Use and Care Guide

Residen al Electric Water Heater Use and Care Guide • 17
INSTALLATION
INSTALLATION
The Electronic Thermostat
IMPORTANT: The Grid Communica-
 on Adaptor must be removed before
a emp ng to access the thermostat.
NOTE: for the Electronic Thermostat
(ET) changes to remain in eff ect the Grid
Communica on Adaptor must not be
reconnected, also read the “Risks During
Opera on” under the “Important Safety
Informa on” sec on. If the instruc ons
are not clear, contact a qualifi ed service
technician.
Water Temperature Adjustment
The Grid Communica on Adaptor is in-
tended to serve as the primary interface
for opera ng the water heater; however,
the Electronic Thermostat (ET) may
control the water heater in the absence
of the Grid Communica on Adaptor.
The Electronic Thermostat consists of
an electronics box that contains a low
voltage power supply, the thermostat
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 thermis-
tor signals and perform switching and
other logic func ons, and a connector to
 e the Electronic Thermostat (ET) to the
Grid Communica on Adaptor located on
the top of the water heater. The majority
of the self-diagnos cs are located in the
Electronic Thermostat (ET), including the
dry-fi re protec on intelligence. The ther-
mostat 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 calling
for heat.
Diagnos c LED Light
The Green/Red LED light indicates the
status of the electronic thermostat (See
Figure 8).
• Green LED will signal normal opera-
 on. The green LED will blink 2  mes
per second to indicate that power is ap-
plied 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 electronic
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 second off
period.
The number of fl ashes indicates the
fault code number.
(See diagnos c code chart sec on in
this manual).
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 remains. 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.
Adjust the thermostat to the desired
temperature se ng using the “Setpoint
Knob”. NOTE: If the system diagnos c
yields any codes, reference the Diagnos-
 c Code sec on in this manual.
Figure 8
Electronic Thermostat (ET)
Diagnostic
LED Light
ECO Reset
Button
Setpoint
Knob
Remove Only After Power Is
Turned O When Replacing Element.
Plastic Guard
Upper
Element
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.
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.
Figure 9
Electronic
Thermostat (ET)
Setpoint
Knob
Thermistor
Wire Harness
Access Door