Air Conditioning / August 4, 2020

AC Hard Start: Causes and Solutions

Your air conditioner (AC) has a hard start if it struggles to start. You might have to turn on the AC multiple times before it runs. Below are some causes of this issue and solutions for a hard start.


A hard start typically occurs due to malfunctions that affect the normal operations of the AC motor. Let’s discover some of those malfunctions.

Low Voltage

An AC requires more electricity to start than to run. A central AC can draw as much as 5,000 watts of electricity during startup. The startup power draw is so high that the AC comes with a capacitor to help start the motor. However, the AC still requires power from the mains, and low voltage can trigger a hard start. A brownout or electrical malfunction can cause low voltage.

Bad Capacitor

A bad capacitor won’t provide an adequate power boost to start the AC motor. Causes of capacitor failure include:

  • Aging
  • Power surge
  • Overheating
  • Mechanical damage

Capacitor failure can affect other operations of the AC, such as fan rotation.

Unbalanced Pressure

The AC compressor increases refrigerant pressure. The pressure increase facilitates refrigerant flow with minimal energy consumption. However, a problem arises if something stops the AC in the middle of its run cycle when the pressure is high on one side and low on the other side. In such a case, the compressor might struggle to resume its cycle once you restart the AC.


Your AC has a finite lifespan. Major components of the AC will start to fail as the AC nears its end of life. The wear and tear on the motor might cause it to fail and struggle to start.

Seized Compressor

Lastly, the AC might also experience a hard start if the compressor has seized. A seized compressor means the pistons in the compressor motor run tight and don’t turn easily. Inadequate lubrication, for example, due to oil leakage, is a common reason for compressor seizes.


The solution to a hard start problem depends on its underlying cause. Thus, the first step is to diagnose the problem. Below are some of the typical solutions, depending on the problem.

Let It Cool

Let the AC cool in case something interrupted its run cycle and triggered a refrigerant pressure imbalance. The pressure will equalize after some time, and the AC will start as usual.

Fix the Malfunction

In case a malfunction has caused the hard start, then the only solution is to fix the underlying problem. For example, if the capacitor has failed, then you must replace the capacitor to deal with the hard start.

Install a Hard Start Kit

If wear and tear have caused the hard start, then the AC might need a hard start kit. The hard start kit is a capacitor-relay combination to boost the AC’s power during startup. Note that the hard start kit is only a temporary solution if the AC is aging — it won’t solve the problem forever.

Replace the AC

If all of the above solutions fail, then you have no option but to replace the AC. Certainly, replacement is the best option if the AC is near the end of its lifespan. With an aging AC, a compressor replacement is not cost-effective because other major components of the AC may also need replacement.

You won’t know why your AC has a hard start if you don’t get a professional diagnosis. Mauzy Heating, Air & Solar has the resources and experience to diagnose and fix all your AC problems. Contact us today so that we can diagnose your AC’s hard start and fix it so that you can enjoy comfortable temperatures again.

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