As the condenser has no moving parts, the usual wear and tear rules don’t tend to apply.
However, condenser complications are a common cause of system break-downs.
Condenser with airflow restriction - external
Usually from insects or grass seeds clogging the finning. However, airflow restriction may also be caused by insect screens, oil coolers and other obstructions which restrict airflow.
Condenser with airflow deficiency
Insufficient airflow due to electric or viscous fan(s) not operating correctly, low voltage, the fan incorrectly positioned in shroud, or the condenser placed too far from the radiator.
Condenser with internal blockage
May be caused by particles from another component such as a failed compressor or other component affected by internal corrosion from moisture due to contaminated oil/refrigerant. Internal condenser blockages are usually only partial, in which case vapour is fed to the receiver-drier and TX valve, with resultant reduced performance. A special note as to parallel and sub-cool condensers: they cannot be flushed clean as flushing solvent will only take the path of least restriction, and will not clean the whole condenser. Note too that a parallel or sub-cool condenser can be up to two thirds blocked without showing any signs of flow restriction. To be sure, in the event of a full compressor failure on a system with a parallel flow or sub-cool condenser, it must be replaced.
Condenser with leaks - inherent
Rare in good quality condensers. Can occur from age, physical damage, or corrosion. Core leaks are common in poor quality condensers, often aggravated by high head pressure in/from the compressor.
Condenser with leaks - fittings
Usually caused by bad installation techniques such as re-using old O-rings, failure to lubricate fittings or failure to line-up fittings prior to tightening.