All Airwell error codes
This page brings together Airwell error codes sorted by type of fault: what each code means, its likely causes, and what you can safely check before calling a professional.
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The Airwell codes on this page, grouped by type of fault.
Temperature sensor — Airwell
These codes indicate a sensor that’s no longer returning a consistent value. The fault almost always comes from the sensor itself or its connector, rarely from the unit.
Code E1Medium severityair-to-air
Indoor / outdoor unit communication fault
Possible causes
- Faulty connecting cable
- Poor connection
- Indoor or outdoor control board
Models affected: HDLB, HDHB, YDAB, YNAB
This fault requires a qualified technician. Do not open the unit.
Code E2Medium severityair-to-air
Zero crossing protection
Possible causes
- Disrupted power supply
- Faulty indoor control board
Models affected: HDLB, HDHB, YDAB
This fault requires a qualified technician. Do not open the unit.
Code E3Medium severityair-to-air
Indoor fan motor fault
Possible causes
- Faulty indoor fan motor
- Blocked fan blade
- Indoor control board
Models affected: YDAB, YNAB
This fault requires a qualified technician. Do not open the unit.
Code E4Medium severityair-to-air
Indoor ambient temperature sensor fault (T1)
Possible causes
- T1 sensor disconnected or short-circuited
- Sensor wiring
- Indoor control board
Models affected: YDAB, YNAB
This fault requires a qualified technician. Do not open the unit.
Fan — Airwell
The fan expels or draws in heat. If it’s blocked or faulty, pressure rises and triggers a shutdown.
Code F3Medium severityair-to-air
Discharge temperature sensor fault (Tp)
Possible causes
- Tp sensor disconnected or short-circuited
- Sensor wiring
- Outdoor control board
Models affected: HDLB, HDHB
This fault requires a qualified technician. Do not open the unit.
Code F4Medium severityair-to-air
Outdoor unit EEPROM parameter error
Possible causes
- Faulty outdoor control board
- Corrupted EEPROM
Models affected: YDAB, YNAB
This fault requires a qualified technician. Do not open the unit.
Low pressure — Airwell
The refrigerant circuit pressure is too low. This often points to a refrigerant shortage, meaning a leak needs to be located.
Code E6Critical severityair-to-air
Communication fault (HDL range)
Possible causes
- Indoor/outdoor connecting cable
- Electronic control board
Models affected: YDAB, YNAB
This fault requires a qualified technician. Do not open the unit.
All Airwell codes published on the site
This list updates automatically whenever a new guide is added.
Technical information provided for guidance only, based on manufacturer documentation and field feedback. It does not replace a diagnosis by a qualified professional. Found an error on this page? Report it.