F4
Lloyd Split AC
Severity: ModerateWhat Does This Error Mean?
F4 on a Lloyd AC means the outdoor coil temperature thermistor has a fault. This sensor monitors the outdoor heat exchanger temperature to protect the compressor and control the refrigerant cycle. A failed or disconnected thermistor triggers F4 and the compressor stops.
Affected Models
- Lloyd Inverter Split AC (all capacities)
- Lloyd 3 Star Inverter
- Lloyd 5 Star Inverter
- Lloyd GLS series
- Lloyd LS series Inverter
Common Causes
- Outdoor coil thermistor failed — resistance outside the acceptable range
- Thermistor clip dislodged from the outdoor condenser coil pipe
- Wiring to the thermistor corroded or broken from weather exposure
- Connector at the outdoor PCB loose or moisture-damaged
- Outdoor PCB fault causing incorrect reading of the coil sensor
How to Fix It
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Power off at the remote and circuit breaker. Wait 5 minutes and restart.
If F4 clears and the AC runs normally, monitor for recurrence. Persistent F4 confirms the thermistor has failed.
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Ensure the outdoor unit has full ventilation clearance on all sides.
A blocked outdoor unit overheats the condenser coil, which can push a borderline thermistor into fault range.
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Call Lloyd service (1800-315-1111) if F4 persists.
The technician will test outdoor coil thermistor resistance and replace if outside specification.
When to Call a Professional
F4 requires a Lloyd (Havells) authorised technician — do not open the outdoor unit. Lloyd customer care: 1800-315-1111.
Frequently Asked Questions
How much does Lloyd AC F4 repair cost?
An outdoor coil thermistor typically costs Rs 200–500 for the part. With the Lloyd service visit and labour, total repair is usually Rs 900–2,000. Under warranty, the repair is covered at no cost — keep your purchase invoice available.