Whirlpool 4 User Manual

12

IMPORTANT: The Energy Smart

®

 Module (ESM) must 

be removed before attempting to access the thermostat. 

NOTE: for the Electronic Thermostat (ET) changes to re-

main in effect the Energy Smart

®

 Module (ESM) must not 

be reconnected, also read the “Water Temperature Regu-

lation” under the “Operating Your Water Heater” section. If 

the instructions are not clear, contact a qualifi ed person.

The Energy Smart

®

 Module (ESM) is intended to serve 

as the primary interface for operating the water heater; 

however, the Electronic Thermostat (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 thermostat 

set point knob, relays to switch between the upper and 

lower heating elements, one control thermistor, a connec-

tor for the lower element control thermistor, microelectron-

ics to convert the thermistor signals and perform switch-

ing and other logic functions, and a connector to tie the 

Electronic Thermostat (ET) to the Energy Smart

®

 Module 

(ESM) located on the front of the water heater jacket. The 

majority of the self-diagnostics are located in the Electronic 

Thermostat (ET), including the dry-fi re protection intelli-

gence. The thermostat circuit is designed so that when the 

upper heating element calls for heat, the power is directed 

to that element even if the lower element is also calling for 

heat. 

The Green/Red LED light indicates the status of the elec-

tronic thermostat (See Figure 10A).

•

 Green LED will signal normal operation. The green 

LED will blink 2 times per second to indicate that power is 

applied to the upper heating element and at a faster rate 

(4 times per second) to indicate that the lower heating ele-

ment 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 diagnostic code chart section in this manual).

 After the last 1/2 second “on” period, the LED will remain 

off until a total of 5 seconds has elapsed for the fault in-

dication cycle (there is a 5 seconds delay before the fault 

fl ash pattern repeats). After the 5 seconds are completed, 

the fault indication cycle is repeated starting 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 time. NOTE: the green LED is turned off when a fault 

code is being displayed, even though the heater may be 

operating in limp mode with an element on.

 

 

See diagnos-

tic code chart section in this manual.

If the Energy Smart

®

 Module (ESM) is not working, simply 

unplug the interface module and turn the set point knob 

on the Electronic Thermostat (ET) to the desired tempera-

ture (See Figures 10A  & 10B). To replace a broken or 

damaged ESM module, see page 22 for ordering informa-

tion.

NOTE: Smart Grid will be disabled when the Energy 

Smart

®

 Module (ESM) is disconnected from the junction 

box wiring harness.