background image

Temperature Sensors

Sensor

Description

(wire color)

Normal tem-

perature Range

Resistance 

range in ohms

Resistance at 

77º F

T2

Tank (white)

30º F-160º F

34K-1.75K

10K

T3a

Evaporator 

Inlet (red)

15º F-130º F

57K-3K

10K

T3b

Evaporator 

Outlet (white)

15º F-130º F

57K-3K

10K

T4

Compressor 

Outlet (blue)

30º F-250º F

188K-3K

55K

T5

Ambient (yellow)

15º F-130º F

57K-3K

10K

SERVICE MODE

The Service Mode can be accessed by pressing and holding the UP Arrow 

and Enter buttons simultaneously for 5 seconds.  You will first hear a 

single beep when pressing the buttons, then a two-tone sound indicating 

the action was successful.  A moment later, you will see the first display of 

the thermistor T2 alternating with its temperature displayed in the units 

selected (degrees F or C).  The Service Mode will time out after 15 minutes 

of button inactivity.
Five functions are available in Service Mode: View Thermistors, Heating 

Component Status and Control, View Faults and Counters, Personality, 

and Software Revision. You may switch from one function to another 

by pressing the Mode button.  The operating mode LED will illuminate 

to indicate which service mode is selected.  An explanation of the five 

functions follows:
View Thermistor (Hidden LED) - Each of the 5 thermistors can be 

monitored for the temperature they sense.  The thermistor designation 

appears on the display and alternates with the temperature in degrees 

of the units selected - Fahrenheit or Celsius.  Pressing the Down Arrow 

button switches the display to the next thermistor in the list.  The following 

table shows the thermistors’ designations and their function in the unit.

Designation

Function

T2

Tank (Water) Temperature

T3a

Evaporator Inlet Temperature

T3b

Evaporator Outlet Temperature

T4

Compressor Discharge Temperature

T5

Ambient Air Temperature

Heating Component Status and Control, EEV Operation (Heat Pump 

(Only) LED) - This function displays the status (on/off) for each of the 

heating components - Lower Element, Upper Element, Compressor (with 

fan), and Fan - and allows you to turn it on or off.  The first component 

is the Lower electric element (LE).  On status is signified by a 1 and off is 

0.  Pressing the Down Arrow button switches to the Upper Element (UE).  

Pressing Down Arrow again switches to the Compressor (with fan) (Co).  

Pressing the Down Arrow once more switches to the fan (Fn) .  Only one 

component can be on at one time.  The electric elements will only stay 

on for 5 minutes without refreshing by pressing any button on the front 

panel.  The compressor timeout is 10 minutes. Press the Down Arrow 

button again to check EEV Operation.  The position will be displayed.  Press 

the Enter button to open the EEV in increments of 10, from 80 to 450.  

After reaching 450, pressing Enter will close the valve in increments of 10.
View Faults and Counters (Hybrid LED) - The control counts the number of 

times a fault is recorded. A fault code is not displayed until the number of 

counts in the fault table (refer to page 2) has been reached. For example, 

if the upper element fails to draw current each time the control energizes 

the upper element, the count will increase by 1. However, if the element 

responds normally, the count will decrement by 1.
The View Faults and Counters function displays any fault codes in the 

system. Pressing the Down Arrow takes you to the next fault code, if 

any. If no fault codes are active, “- - -” is displayed. Pressing the Filter 

button switches the display to the fault counters. The displayed fault 

code alternates with its count value. For example, if the thermistor T3a 

has registered 3 failures, its value will be 3 and the display will alternate 

between “F5” and “3”.
To clear all fault codes and fault counters, press and hold the Enter button 

for 5 seconds and listen for the beep.
Personality (Electric (Only) LED)- This function allows the user to verify that 

the correct parameter set has been programmed into the control board 

(refer to Personality Table on page 2).  The Personality allows the software 

to properly control the heating system.  The Personality of the water 

heater cannot be changed, except by replacing the control board.
Software Revision (Vacation LED) - This function allows the user to view 

the software revision that is programmed into the control.  If the software 

revision is not correct, the correct revision should be uploaded.
Exiting Service Mode - To exit Service Mode without waiting for 15 minute 

timeout, press and hold the Up Arrow and Down Arrow simultaneously for 

5 seconds and listen for two beeps.

T2 Tank Sensor

T3b Evaporator

Outlet Sensor

T4 Compressor

   Outlet Sensor

T3a Evaporator

     

Inlet Sensor

T5 Ambient Air

        Sensor

Condensate

Overflow Sensor

          31-75036-1

  03-15

PASS/FAIL COMPONENT OPERATION

Selected Mode

SS

LE 

UE

Temporary Mode (if component failure is detected)

Any

P

P

P

Runs in selected mode

Any

F

P

P

Electric (Only) mode

Hybrid

P

F

P

Hybrid Mode (but uses SS when LE is called for)

Electric (Only) 

P

F

P

Electric (Only) Mode (UE only)

Heat Pump (Only)

P

F

P

Heat Pump (Only) mode

High Demand/Boost

P

F

P

High Demand/Boost (but uses SS when LE is called for)

Hybrid

P

P

F

Control uses SS and LE based on demand algorithm

Electric (Only)

P

P

F

LE Only Mode

Heat Pump (Only)

P

P

F

Heat Pump (Only) Mode

High Demand/Boost

P

P

F

High Demand/Boost (but uses LE when UE called for)

Any

F

F

P

Electric (Only) Mode (UE only)

Any

P

F

F

Heat Pump (Only) Mode

Any 

F

P

F

LE Only Mode

Any

F

F

F

Electric (Only) Mode, displays 1 fault codes

SS = Sealed System

LE = Lower Element

UE= Upper Element

Printed in USA

Отзывы: