How Often To Replace Capacitor On Ac Unit

4 min read Jun 26, 2024
How Often To Replace Capacitor On Ac Unit

How Often to Replace Capacitor on AC Unit: A Guide


The capacitor is a vital component of an air conditioning (AC) unit, responsible for storing electrical energy and providing power to the compressor and fan motors. Over time, the capacitor can deteriorate, reducing the efficiency and performance of the AC unit. In this article, we will explore how often to replace the capacitor on an AC unit and signs that indicate it's time for a replacement.

Factors Affecting Capacitor Replacement

Several factors can influence the lifespan of a capacitor and determine how often it needs to be replaced. These include:


  • Most capacitors have a lifespan of 5 to 7 years, depending on the quality and usage of the AC unit.
  • Capacitors used in AC units operating in coastal areas or exposed to high humidity may need to be replaced more frequently.


  • AC units that operate continuously or are subjected to heavy loads may require more frequent capacitor replacement.
  • Units that are turned on and off frequently may also reduce the capacitor's lifespan.


  • High-quality capacitors may last longer than lower-quality ones.
  • Capacitors from reputable manufacturers may have a longer lifespan than those from lesser-known brands.

Signs of Capacitor Failure

Here are some common signs that indicate the capacitor needs to be replaced:

Unusual Noises

  • Unusual humming, buzzing, or clicking sounds from the AC unit may indicate a failing capacitor.

Reduced Performance

  • If the AC unit is not cooling or heating properly, it could be a sign of a failing capacitor.

Increased Energy Bills

  • A failing capacitor can cause the AC unit to consume more energy, leading to higher energy bills.

Visible Damage

  • If the capacitor is physically damaged, cracked, or corroded, it's a clear indication that it needs to be replaced.

How Often to Replace Capacitor on AC Unit

As a general rule, it's recommended to replace the capacitor every 5 to 7 years, depending on the factors mentioned above. However, if you notice any of the signs mentioned above, it's best to replace the capacitor immediately to avoid further damage to the AC unit.


Replacing the capacitor on an AC unit is a relatively simple and inexpensive task, but it's essential to ensure the unit operates efficiently and effectively. By understanding the factors that affect capacitor lifespan and recognizing the signs of capacitor failure, you can determine how often to replace the capacitor on your AC unit and ensure optimal performance. If you're unsure about replacing the capacitor, it's always best to consult a professional HVAC technician.