Compressor replacement is the single most expensive AC repair. Knowing when to replace versus when to rewind versus when to scrap the whole unit can save you thousands of rupees. Here are the seven warning signs that the compressor itself is finished.
1. Hot suction line
The large copper line returning to the compressor should be cold to the touch during operation. A hot suction line means the compressor is struggling and overheating internally.
2. Hard starting / repeated trips
If the compressor hums for 5–10 seconds before starting (or fails to start until the breaker is reset), suspect either a failed capacitor or a stuck compressor.
3. Loud knocking or banging
Internal mechanical damage — broken valve plates, snapped crankshaft. Replacement only.
4. Burning smell
Windings have shorted. The refrigerant and oil have likely been contaminated; replace compressor, drier, and flush the system.
5. Continuous running, no cooling
Compressor turns but doesnt pump. Either a blown valve plate or a failed scroll set — replacement required.
6. Tripping the breaker
Repeated breaker trips indicate either a winding short to ground or a locked rotor. Both require replacement.
7. Oil contamination
Burnt-smelling oil drained from the system means the windings degraded. Replace the compressor and aggressively flush before recharging.