E1

Room Temperature Sensor Fault

E2

Evaporator Temperature Sensor Fault

E3

Condenser Temperature Sensor Fault

E4

Water Tank Full — Unit Stopped

E5

System Defect — Contact Service

P1

Water Collection Full (Pump Alert)

CF

Clean Filter Reminder

MECH-ICING

Ice Buildup on Evaporator Coils

MECH-EXHAUST

Exhaust Hose Installation Problem

MECH-NOISE

Unusual Noise or Vibration

MECH-LEAK

Water Leaking from Unit

MECH-REMOTE

Remote Control Not Working

MECH-WONT-START

Unit Will Not Turn On

E1

Room Temperature Sensor Fault

E2

Evaporator Temperature Sensor Fault

E3

Condenser Temperature Sensor Fault

E4

Water Tank Full — Unit Stopped

E5

System Defect — Contact Service

P1

Water Collection Full (Pump Alert)

CF

Clean Filter Reminder

MECH-ICING

Ice Buildup on Evaporator Coils

MECH-EXHAUST

Exhaust Hose Installation Problem

MECH-NOISE

Unusual Noise or Vibration

MECH-LEAK

Water Leaking from Unit

MECH-REMOTE

Remote Control Not Working

MECH-WONT-START

Unit Will Not Turn On

FILTER-LIGHT

Filter Replacement Indicator Light On (Red)

PREFILTER-LIGHT

Pre-Filter Check Indicator Light On

MECH-NOISE

Loud or Unusual Noise

MECH-WEAK-AIRFLOW

Reduced Airflow Output

MECH-WONT-START

Unit Will Not Turn On

MECH-ODOR

Unpleasant Smell from Unit

MECH-FILTER-RESET

Filter Reset Button Not Working

COOL-ON-FLASH

"Cool On" Flashing on Display

HEAT-ON-FLASH

"Heat On" Flashing on Display

AUX-HEAT

"Aux Heat" Displayed

EM-HEAT

"Em Heat" or Emergency Heat Mode

WAIT

"Wait" Message on Display

RECOVERY

"Recovery" Message on Display

BLANK-SCREEN

Blank/Dead Display — No Power

ERR

"Err" Displayed on Screen

REPLACE-BATT

"Replace Battery" Warning

FILTER-REMIND

"Filter" Reminder Displayed

BLOWN-FUSE

HVAC Control Board Fuse Blown

NO-C-WIRE

No C-Wire — Thermostat Won't Power On

WRONG-WIRING

Incorrect Wiring Configuration

NO-COOL

Thermostat Calling for Cool but AC Not Running

NO-HEAT

Thermostat Calling for Heat but No Heat

SHORT-CYCLE

System Short Cycling (Rapid On/Off)

FAN-WONT-STOP

Fan Running Constantly

WIFI-DROP

WiFi Connection Lost

APP-OFFLINE

Thermostat Shows Offline in App

TEMP-WRONG

Displayed Temperature Reading Is Wrong

WONT-SWITCH

Won't Switch Between Heat and Cool

ROOM-UNEVEN

Uneven Temperatures Between Rooms

TOUCH-UNRESPONSIVE

Touchscreen Not Responding

SCREEN-DIM

Display Very Dim or Hard to Read

SCHED-NOT-FOLLOWED

Schedule Not Being Followed

COOL-ON-FLASH

"Cool On" Flashing on Display

HEAT-ON-FLASH

"Heat On" Flashing on Display

AUX-HEAT

"Aux Heat" Displayed

EM-HEAT

"Em Heat" or Emergency Heat Mode

WAIT

"Wait" Message on Display

RECOVERY

"Recovery" Message on Display

BLANK-SCREEN

Blank/Dead Display — No Power

ERR

"Err" Displayed on Screen

REPLACE-BATT

"Replace Battery" Warning

FILTER-REMIND

"Filter" Reminder Displayed

BLOWN-FUSE

HVAC Control Board Fuse Blown

NO-C-WIRE

No C-Wire — Thermostat Won't Power On

WRONG-WIRING

Incorrect Wiring Configuration

NO-COOL

Thermostat Calling for Cool but AC Not Running

NO-HEAT

Thermostat Calling for Heat but No Heat

SHORT-CYCLE

System Short Cycling (Rapid On/Off)

FAN-WONT-STOP

Fan Running Constantly

WIFI-DROP

WiFi Connection Lost

APP-OFFLINE

Thermostat Shows Offline in App

TEMP-WRONG

Displayed Temperature Reading Is Wrong

WONT-SWITCH

Won't Switch Between Heat and Cool

ROOM-UNEVEN

Uneven Temperatures Between Rooms

TOUCH-UNRESPONSIVE

Touchscreen Not Responding

SCREEN-DIM

Display Very Dim or Hard to Read

SCHED-NOT-FOLLOWED

Schedule Not Being Followed

GEOFENCE-ISSUE

Geofencing Not Working Correctly

SENSOR-OFFLINE

Room Sensor Offline

COOL-ON-FLASH

"Cool On" Flashing on Display

HEAT-ON-FLASH

"Heat On" Flashing on Display

AUX-HEAT

"Aux Heat" Displayed

EM-HEAT

"Em Heat" or Emergency Heat Mode

WAIT

"Wait" Message on Display

RECOVERY

"Recovery" Message on Display

BLANK-SCREEN

Blank/Dead Display — No Power

ERR

"Err" Displayed on Screen

REPLACE-BATT

"Replace Battery" Warning

FILTER-REMIND

"Filter" Reminder Displayed

BLOWN-FUSE

HVAC Control Board Fuse Blown

NO-C-WIRE

No C-Wire — Thermostat Won't Power On

WRONG-WIRING

Incorrect Wiring Configuration

NO-COOL

Thermostat Calling for Cool but AC Not Running

NO-HEAT

Thermostat Calling for Heat but No Heat

SHORT-CYCLE

System Short Cycling (Rapid On/Off)

FAN-WONT-STOP

Fan Running Constantly

WIFI-DROP

WiFi Connection Lost

APP-OFFLINE

Thermostat Shows Offline in App

TEMP-WRONG

Displayed Temperature Reading Is Wrong

WONT-SWITCH

Won't Switch Between Heat and Cool

ROOM-UNEVEN

Uneven Temperatures Between Rooms

TOUCH-UNRESPONSIVE

Touchscreen Not Responding

SCREEN-DIM

Display Very Dim or Hard to Read

SCHED-NOT-FOLLOWED

Schedule Not Being Followed

GEOFENCE-ISSUE

Geofencing Not Working Correctly

SENSOR-OFFLINE

Room Sensor Offline

REDLINK-FAIL

RedLINK Gateway Communication Error

COOL-ON-FLASH

"Cool On" Flashing on Display

HEAT-ON-FLASH

"Heat On" Flashing on Display

AUX-HEAT

"Aux Heat" Displayed

EM-HEAT

"Em Heat" or Emergency Heat Mode

WAIT

"Wait" Message on Display

RECOVERY

"Recovery" Message on Display

BLANK-SCREEN

Blank/Dead Display — No Power

ERR

"Err" Displayed on Screen

REPLACE-BATT

"Replace Battery" Warning

FILTER-REMIND

"Filter" Reminder Displayed

BLOWN-FUSE

HVAC Control Board Fuse Blown

NO-C-WIRE

No C-Wire — Thermostat Won't Power On

WRONG-WIRING

Incorrect Wiring Configuration

NO-COOL

Thermostat Calling for Cool but AC Not Running

NO-HEAT

Thermostat Calling for Heat but No Heat

SHORT-CYCLE

System Short Cycling (Rapid On/Off)

FAN-WONT-STOP

Fan Running Constantly

WIFI-DROP

WiFi Connection Lost

APP-OFFLINE

Thermostat Shows Offline in App

TEMP-WRONG

Displayed Temperature Reading Is Wrong

WONT-SWITCH

Won't Switch Between Heat and Cool

ROOM-UNEVEN

Uneven Temperatures Between Rooms

TOUCH-UNRESPONSIVE

Touchscreen Not Responding

SCREEN-DIM

Display Very Dim or Hard to Read

SCHED-NOT-FOLLOWED

Schedule Not Being Followed

COOL-ON-FLASH

"Cool On" Flashing on Display

HEAT-ON-FLASH

"Heat On" Flashing on Display

AUX-HEAT

"Aux Heat" Displayed

EM-HEAT

"Em Heat" or Emergency Heat Mode

WAIT

"Wait" Message on Display

RECOVERY

"Recovery" Message on Display

BLANK-SCREEN

Blank/Dead Display — No Power

ERR

"Err" Displayed on Screen

REPLACE-BATT

"Replace Battery" Warning

FILTER-REMIND

"Filter" Reminder Displayed

BLOWN-FUSE

HVAC Control Board Fuse Blown

NO-C-WIRE

No C-Wire — Thermostat Won't Power On

WRONG-WIRING

Incorrect Wiring Configuration

NO-COOL

Thermostat Calling for Cool but AC Not Running

NO-HEAT

Thermostat Calling for Heat but No Heat

SHORT-CYCLE

System Short Cycling (Rapid On/Off)

FAN-WONT-STOP

Fan Running Constantly

WIFI-DROP

WiFi Connection Lost

APP-OFFLINE

Thermostat Shows Offline in App

TEMP-WRONG

Displayed Temperature Reading Is Wrong

WONT-SWITCH

Won't Switch Between Heat and Cool

ROOM-UNEVEN

Uneven Temperatures Between Rooms

TOUCH-UNRESPONSIVE

Touchscreen Not Responding

SCREEN-DIM

Display Very Dim or Hard to Read

SCHED-NOT-FOLLOWED

Schedule Not Being Followed

GEOFENCE-ISSUE

Geofencing Not Working Correctly

SENSOR-OFFLINE

Room Sensor Offline

COOL-ON-FLASH

"Cool On" Flashing on Display

HEAT-ON-FLASH

"Heat On" Flashing on Display

AUX-HEAT

"Aux Heat" Displayed

EM-HEAT

"Em Heat" or Emergency Heat Mode

WAIT

"Wait" Message on Display

RECOVERY

"Recovery" Message on Display

BLANK-SCREEN

Blank/Dead Display — No Power

ERR

"Err" Displayed on Screen

REPLACE-BATT

"Replace Battery" Warning

FILTER-REMIND

"Filter" Reminder Displayed

BLOWN-FUSE

HVAC Control Board Fuse Blown

NO-C-WIRE

No C-Wire — Thermostat Won't Power On

WRONG-WIRING

Incorrect Wiring Configuration

NO-COOL

Thermostat Calling for Cool but AC Not Running

NO-HEAT

Thermostat Calling for Heat but No Heat

SHORT-CYCLE

System Short Cycling (Rapid On/Off)

FAN-WONT-STOP

Fan Running Constantly

WIFI-DROP

WiFi Connection Lost

APP-OFFLINE

Thermostat Shows Offline in App

TEMP-WRONG

Displayed Temperature Reading Is Wrong

WONT-SWITCH

Won't Switch Between Heat and Cool

ROOM-UNEVEN

Uneven Temperatures Between Rooms

TOUCH-UNRESPONSIVE

Touchscreen Not Responding

SCREEN-DIM

Display Very Dim or Hard to Read

SCHED-NOT-FOLLOWED

Schedule Not Being Followed

COOL-ON-FLASH

"Cool On" Flashing on Display

HEAT-ON-FLASH

"Heat On" Flashing on Display

AUX-HEAT

"Aux Heat" Displayed

EM-HEAT

"Em Heat" or Emergency Heat Mode

WAIT

"Wait" Message on Display

RECOVERY

"Recovery" Message on Display

BLANK-SCREEN

Blank/Dead Display — No Power

ERR

"Err" Displayed on Screen

REPLACE-BATT

"Replace Battery" Warning

FILTER-REMIND

"Filter" Reminder Displayed

BLOWN-FUSE

HVAC Control Board Fuse Blown

NO-C-WIRE

No C-Wire — Thermostat Won't Power On

WRONG-WIRING

Incorrect Wiring Configuration

NO-COOL

Thermostat Calling for Cool but AC Not Running

NO-HEAT

Thermostat Calling for Heat but No Heat

SHORT-CYCLE

System Short Cycling (Rapid On/Off)

FAN-WONT-STOP

Fan Running Constantly

WIFI-DROP

WiFi Connection Lost

APP-OFFLINE

Thermostat Shows Offline in App

TEMP-WRONG

Displayed Temperature Reading Is Wrong

WONT-SWITCH

Won't Switch Between Heat and Cool

ROOM-UNEVEN

Uneven Temperatures Between Rooms

TOUCH-UNRESPONSIVE

Touchscreen Not Responding

SCREEN-DIM

Display Very Dim or Hard to Read

SCHED-NOT-FOLLOWED

Schedule Not Being Followed

COOL-ON-FLASH

"Cool On" Flashing on Display

HEAT-ON-FLASH

"Heat On" Flashing on Display

AUX-HEAT

"Aux Heat" Displayed

EM-HEAT

"Em Heat" or Emergency Heat Mode

WAIT

"Wait" Message on Display

RECOVERY

"Recovery" Message on Display

BLANK-SCREEN

Blank/Dead Display — No Power

ERR

"Err" Displayed on Screen

REPLACE-BATT

"Replace Battery" Warning

FILTER-REMIND

"Filter" Reminder Displayed

BLOWN-FUSE

HVAC Control Board Fuse Blown

NO-C-WIRE

No C-Wire — Thermostat Won't Power On

WRONG-WIRING

Incorrect Wiring Configuration

NO-COOL

Thermostat Calling for Cool but AC Not Running

NO-HEAT

Thermostat Calling for Heat but No Heat

SHORT-CYCLE

System Short Cycling (Rapid On/Off)

FAN-WONT-STOP

Fan Running Constantly

WIFI-DROP

WiFi Connection Lost

APP-OFFLINE

Thermostat Shows Offline in App

TEMP-WRONG

Displayed Temperature Reading Is Wrong

WONT-SWITCH

Won't Switch Between Heat and Cool

ROOM-UNEVEN

Uneven Temperatures Between Rooms

TOUCH-UNRESPONSIVE

Touchscreen Not Responding

SCREEN-DIM

Display Very Dim or Hard to Read

SCHED-NOT-FOLLOWED

Schedule Not Being Followed

GEOFENCE-ISSUE

Geofencing Not Working Correctly

SENSOR-OFFLINE

Room Sensor Offline

EQUIP-ALERT

Equipment Alert on Display