Lennox SL280UHNV Series

Page 10
TABLE 5 Continued
Code Diagnostic Codes/Status of Equipment Action Required to Clear and Recover
E 124
Active communicating thermostat signal missing for more than 3 min
utes.
Equipment lost communication with the thermostat.
Check four wiring connections, ohm wires and cycle
power at the thermostat. Alert stops all services and
waits for heartbeat message from thermostat (sub
net controller). Cleared after valid thermostat (sub
net controller) message is received.
E 125
Control failed self-check, internal error, failed hardware. Will restart if
error
recovers. Integrated control not communicating. Covers hardware errors
(flame sense circuit faults, pin shorts, etc.).
Hardware problem on the control. Cycle power on
control. Replace if problem prevents service and is
persistent. Critical alert. Cleared 300 seconds after
fault recovered.
E 126
Control internal communication problem. Hardware problem on the control. Cycle power on
control. Replace if problem prevents service and is
persistent. Cleared 300 seconds after fault recov
ered.
E 131
Corrupted control parameters (Verify configuration of system). Communi
cating only.
Reconfigure the system. Replace control if heating
or cooling is not available. Only applicable in the
communicating mode, not in startup. Exit from Com
missioning and Execute 'Set Factory Default mode'.
Control will still operate on default parameter set
tings.
E 180
Outdoor air temperature sensor failure. Only shown if shorted or out-of-
range.
Compare outdoor sensor resistance to temperature/
resistance charts in unit installation instructions.
Replace sensor pack if necessary. At beginning of
(any) configuration, furnace or air handler control
will sense outdoor air and discharge air temperature
sensor(s). If detected (reading in range), appropri
ate feature will be set as 'installed' and that could be
seen in 'About' screen. In normal operation after
control recognizes sensors, alarm will be sent if
valid temperature reading is lost. To get rid of set
ting and alarm, redo configuration and make sure
that temperature sensor is marked as 'not installed'
in Indoor Unit 'About' screen. When Indoor unit con
trol is replaced, thermostat will 'tell' new control if
temperature sensor is in system or not. Clears 30
seconds after fault recovered.
E 200
Hard lockout - Rollout circuit open or previously open. Correct cause of rollout trip, or replace flame rollout
switch. Test furnace operation. Cleared after fault
recovered.
E 201
Indoor blower communication failure - Unable to communicate with blow
er motor.
Indoor blower communication failure (including pow
er outage). Lost communication with indoor blower
motor. Possible causes: motor not powered, loose
wiring. Problem may be on control or motor side.
Cleared after fault recovered.
E 202
Indoor blower motor mis-match - Indoor motor horsepower does not
match unit capacity. See NO TAG.
Incorrect appliance capacity code selected. Check
for proper configuring under: Unit Size Codes for
Furnace/Air Handler on configuration guide or in
installation instructions. Cleared after the correct
match is detected following a reset. (Remove ther
mostat from system while applying power and re
programming.)
E 203
Appliance capacity / size is NOT programmed. Invalid unit codes refer to
configuration flow chart.
No appliance capacity code selected. Check for
proper configuring under: Unit Size Codes for Fur
nace on configuration guide or in installation instruc
tions. Critical Alert. Cleared after valid unit code is
read following a reset. (Remove thermostat from
system while applying power and reprogramming.)
E 204
Gas valve mis-wired. Check gas valve operation and wiring. Clears when
repaired.
E 205
Gas valve control relay contact shorted. Check wiring on control and gas valve. If wiring is
correct, replace control.