U0 Daikin — Refrigerant Leak / Low Charge
At a glance
- Severity
- FAULT STOP
- Domain
- AIR_CONDITIONING_SYSTEM
- Reference standard
- EN 378 / F-Gas EU 517/2014
- Product / context
- Refrigerant shortage
What it means
The system is running with reduced refrigerant charge; the controller may infer this through pressures, temperatures or internal protection algorithms.
Probable causes
- Loose or badly remade flare joints
- Leak on indoor or outdoor coil
- Previous intervention without restoring the correct refrigerant weight
Reference values
| refrigerant charge | {"subcooling_K":"5-8 (optimal)","superheat_K":"5-8 at the evaporator","leak_search":"electronic detector / UV / nitrogen+soap","vacuum":"< 500 µm holding 30 min"} |
|---|
Full guided diagnosis in the app
The diagnostic tree for this fault has 3 guided steps with measurements, checks and resolutions. You'll find it in HVACIQ, one of the five IndexOS apps: free, works offline.
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