Appendix A. Diagnostic Information & Hidden Menu Tables - Lennox L7742U Programming And Application Manual

Appendix B. Diagnostic Information and Hidden Menu Tables
Diagnostic Information Table
Message
Type
Condition
Error AC power loss with
battery (Battery Model
Only)
Error AC power loss without
battery: AC power loss
for greater than 250ms
Error CPU memory error
Note: If this Error oc-
curs the display goes
blank and all relays are
disabled.
Error ROM error
Note: If this Error oc-
curs the display goes
blank and all relays are
disabled.
Error Hi temperature protec-
tion: ambient temp. ex-
ceeds 96F (35.6C)
Error Local Temp Sensor er-
ror: local temp sensor
reads out of range
−40F to 158F
Error EEPROM error (Power
ON)
Error EEPROM error (Oper-
ating)
Error Outdoor Sensor error
with Humiditrol enable
(OR ODT was used for
balance point control
only): outdoor sensor
reads out of range
(−50F to 180F)
506061−01 06/08
Display Text (Screen1) Display Text (Screen2)
*No message
*No message
*Not operate
*Not operate
*No message
TEMP SENSOR ERROR Contact Info. Screen
CALL FOR SERVICE
MEMORY ERROR Contact Info. Screen
CALL FOR SERVICE
MEMORY ERROR Contact Info. Screen
CALL FOR SERVICE
NO OUTDOOR SENSOR See REMIND/SERVICE
REMIND SERVICE notes
Priority System Action
Thermostat can detect AC power loss and Stat. will operate
with batteries.
Super Cap Or Lithium Battery will remember the clock. All
outputs will be off and O/B will remember the last state.
All stages of heat are turned off.
0−Red Indoor temp is displayed as "EE" on the home screen. This
Alert will STOP all temperature related operation.
0−Red System shall restore everything to Energy Star Default and
Alert operate. If lithium Bat OR Super Cap has Charge, it will
remember the previous stored settings.
0−Red System shall operate in normal mode operation until power
Alert off.
1−Criti- No Humiditrol or Humidity operation is run. D terminal stays
cal activated and other operation will keep working.
The display of Outdoor sensor from HOME will be turned
OFF. If user turns on the display from USER SETTINGS,
this error is displayed again.
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Action to Clear / Recovery
Condition
When AC power recovers stat. can
detect and will operate on AC.
When AC power (or battery power)
is restored, normal operation re-
sumes.
If temperature goes down, it will
start working again.
User have to call the number from
contact information screen and
have someone come and replace
the stat. OR If the sensor read
back to with in the normal operat-
ing range, the error message will
be cleared. Start working again.
User shall call the dealer.
User shall call the dealer.
If the outdoor sensor reads a val-
ue within its normal range. (User
can call the dealer to replace out-
door sensor)
table continued on next page