5 Signs Your AC System's Capacitor Is Starting to Fail

Posted on: 8 October 2018


All most people know about AC systems is that turning them on provides cool, refreshing air throughout the house. Unfortunately, there are always things that can go wrong, and then you'll need to start thinking about which part might be to blame.

Consider the capacitor. This small, cylindrical part is responsible for sending power to the motor that runs your AC system; it provides the initial power boost and then supplies continuous power to keep things running. When the capacitor starts to fail, the fans may not spin, and the compressor may not move. You can get away with a bad capacitor for a little while, but you should really get yours replaced prior to total failure.

Here are just five signs your AC system's capacitor has gone bad.

1. No Cold Air

An AC system that doesn't provide cold air is a sad thing indeed, especially when you're in the middle of a heatwave. It creates what is called 'phase shifted current,' which is necessary to ensure other parts do their job. If it starts to fail, you may notice your AC system isn't supplying cold air. At first, this may only happen intermittently. If you don't address the problem, cold air will soon become a distant memory.

2. Trouble Starting

Often one of the first signs your AC capacitor needs replacing is trouble getting started. At first, you might find the AC system failing to start properly and then working when you try again. It can be tempting to dismiss the problem, but failed starts are going to get more frequent. Eventually, your AC unit won't start at all.

3. Unexpected Turning Off

Even if your AC system is turning on fine, a bad capacitor may mean it doesn't stay on. If the capacitor is starting to fail, your AC system may run briefly and then shut off. Again, this will happen intermittently at first and then become more frequent.

4. Higher Energy Bills

If you're the sort of person who scrutinizes their energy bill, you might get an early warning sign of a bad capacitor in your statements. When the AC capacitor isn't working properly, your system is forced to work harder. As such, it's going to consume more power.

5. Humming Noise

If you notice a humming noise from your AC system, you should call in a professional as soon as you can, regardless of the problem. There are several reasons this could be happening, and a failing capacitor is one of them. 

For more information, contact your local electrical contractor today.