Low Defrost Alarm (Error Code 44): Causes and Fixes
What triggers the Low Defrost alarm and how to clear it
What is the Low Defrost alarm?
The Low Defrost alarm indicates that the heat pump's defrost cycle is not performing as expected. This can happen during periods of low outdoor temperatures when ice builds up on the outdoor unit.
Why it happens
- Outdoor temperature is very low (below –10°C) for an extended period
- Airflow around the outdoor unit is restricted (e.g. snow, ice buildup, obstruction)
- Refrigerant level or pressure issue
- Sensor fault
What to check immediately
- Inspect the outdoor unit for ice buildup or obstructions (snow, debris, vegetation).
- Ensure there is at least 30–50 cm of clear space around the air intake and outlet.
- Do not pour water over the unit to de-ice — allow it to defrost naturally or via the unit's built-in defrost cycle.
Resetting the alarm
- Once the obstruction or icing issue is resolved, navigate to Alarms on the display.
- Select and reset the Low Defrost alarm.
- Monitor the unit for the next few hours to ensure it does not recur.
Recurring alarms
If the alarm returns repeatedly without clear obstruction, there may be a refrigerant or sensor issue. Contact support for a service appointment.
Email: support@qvantum.com