AC Hard Start: Understanding the Function, Benefits, and Troubleshooting

Is your air conditioning unit making weird noises? Is it struggling to turn on and stay on? Your system is probably dealing with a hard start. With proper knowledge of AC mechanisms, you can fix it yourself. A hard start kit was created to solve this problem and get your unit working again.

An AC hard start kit is designed to give a jolt of electricity to your compressor. This jolt makes your compressor turn on when it’s struggling and uses electricity more efficiently. It is an excellent investment that will save you money, stress, and make your system function at high performance for many years.

In this article, you will learn what a hard start kit is, what it does, and how it can benefit you. You will learn its advantages, when to use it, and how it can lower your electricity bill. Not only that, but it can also make your AC system last many more years than it would otherwise.

What Exactly is a Hard Start and What Causes It?

To understand exactly what hard starts are, you need to understand the basics of how an AC unit works. The source of the hard start problem is the AC compressor. Imagine that the compressor is the heart of your air conditioner.

It powers the system and works the hardest out of all the other mechanisms. Ever hear a whirring sound come on after setting your thermostat to cool? That’s your compressor working.

Your compressor increases pressure and temperature on the refrigerant. Refrigerant is a chemical compound that absorbs heat in your environment. As your refrigerant runs through your compressor, it will provide cool air to your house.

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Basically, if you don’t have a working compressor, you don’t have a working AC system. Over time, this compressor suffers wear and tear. It can get damaged and strained because it requires a large amount of electricity to turn on and cool your house.

You now understand parts of the AC unit, but what is a hard start? A hard start is when your AC compressor is struggling to turn on and stay on. Knowing what caused a hard start can enable you to fix it yourself and save money on calling a professional. So, what causes a hard start?

The capacitator, a mechanism that provides the initial jolt of electricity to start your AC, could be damaged. It can lose the ability to store temporary voltage, thus resulting in a hard start.

You can tell this is happening if you hear a clicking sound when you start your AC. If your capacitor isn’t working, your compressor won’t be working either. The compressor depends on the capacitor to turn on.

A worn-down compressor can also be the source of the problem. Over time, the compressor motor can lose lubrication, which causes makes it difficult for it to move. Without movement, it can’t turn on and power your system.

Luckily, hard start kits where invented to solve these very problems.

What is an AC Hard Start Kit?

Basically, a hard start kit works as a capacitor and provides that jolt of electricity needed to get things going. It generally comes in two parts: a capacitor and potential relay.

With a hard start kit, you can store the energy needed within the unit, and shorten the amount of time it takes for your AC to turn on. Basically, it will run better, more smoothly, and more efficiently. This also reduces damage to other parts of your AC unit and prolongs the life of your system.

Your compressor uses a lot of energy. In fact, when your compressor turns on, it requires 4-8 times more electric current than your unit regularly needs. Normal capacitators that provide this jolt of electricity aren’t really equipped to handle the high amounts of voltage. It isn’t as effective or efficient.

AC Hard Start Kit

To better understand this, imagine your capacitor is a great marathon runner, but a poor sprinter.  A hard start kit is the opposite: they can handle the power surge and sprint without issue. This gets your compressor running at its optimal speed almost instantly. The compressor won’t struggle as much to turn on, and your regular capacitor can run long-term without issue.

Hard start kits are designed to work long-term. A good quality model can even last decades. You can even install it yourself without professional help. All you have to do is go to your outside AC unit, connect the correct wires, and you’ll have yourself a much better functioning system.

As we stated earlier, a hard start kit is usually two parts: a capacitor and a potential relay. The capacitator turns on the compressor. Potential relays are a mechanism that sense voltage in the system.

It discerns how much voltage is needed for the starting system and when it has enough. Without a potential relay, your capacitator could explode or destroy the motor within just a few seconds. Both the capacitor and potential relay are necessary in a hard start kit.

Many people buy hard start kits before their AC unit begins to deteriorate. Hard start kits are incredibly effective at preserving the performance of your system, even if there’s nothing currently wrong with it.

If you’re still wondering if it’s worth it to get a hard start kit, let’s move on to the advantages of having one.

Is a Hard Start Kit Worth Buying?

If you want your AC system to last a long time, a lower electricity bill, and your compressor to work consistently, than a hard start kit is absolutely worth it.

Your other option is to replace the compressor. No one wants to pay to replace a compressor. That can cost anywhere from $1,200 to $2,500 to replace, while hard start kits are much cheaper. We’ll discuss hard start prices in the next section.

Not only are compressors expensive, but they are also a pain to replace. Sometimes, it’s not even worth the cost and effort. You can extend the lifespan of your existing compressor with a hard start kit. This saves you money and time.

Your compressor gets worn out over time. A hard start kit minimizes wear and tear on your compressor. Every time your compressor starts up, it causes strain. The longer it takes for your compressor to start up, the more energy it will require.

Excessive heat from the access electricity can damage your compressors coils. If you allow this strain to continue long term, your compressor will start to suffer. A hard start can both fix and prevent this strain, makings sure your compressor lives a long, long time.

A compressor isn’t always the reason for a hard start. Sometimes, it can be caused by low voltage or improper wiring too.

Your compressor can be in perfect condition, but when it just doesn’t have the voltage it needs, it will struggle to turn on. Luckily, a hard start kit can fix that problem too by sensing how much voltage the compressor needs and supplying it almost instantly. Again, this will make your system last years longer than it would otherwise.

Electricity bills are a pain, and a hard start caused by a damaged compressor will only raise it. Hard start kits will save your AC system and lower your electricity bill. Who doesn’t love to save money?

A worn-down compressor will draw more power than it needs to start, raising your electricity bill. A hard start kit will provide the minimum amount it needs to work. Once again, this efficiency of energy also enables your unit to last a long time.

How Much Does a Hard Start Kit Cost?

Hard start kits don’t have to break the bank, you can get one anywhere from $15 to $60. This is a much better investment than replacing your compressor or your whole AC unit. However, there’s a lot of different hard start kits on the market. How do you know which one to get?

First, you need to know which kind of kit you need. There are two main types: one with three wires and an external relay or a two-wire one with a relay built in.

You determine which one you need by finding out how many tons your AC uses. A ton is the unit used to measure the cooling capacity of your AC. If your AC is 2-3 tons, then you need a hard start kit with the same tonnage. Most HVAC packages are 2-3 tons, but if you have a large home, it may be greater. If you get the wrong kit for your system, it will be ineffective at best and damaging at worst.

A PTC (positive temperature coefficient) hard start kit is a 2-wire kit. It’s considered to be one of the most convenient kits. This can be purchased for as low as $15. This is one of the cheaper models available. However, they are not quite as precise. They may use slightly more energy than necessary.

An MPR (mechanical potential relay) hard start hit is known for being one of the most reliable kits. It is also generally more recommended by technicians for this reason. Another 2-wire kit, it should be pretty easy to install. You can get this one for as low as $30.

If you hire a technician to install your hard start kit, expect to pay at least $100. However, you can probably do it by yourself.

Wrapping Things Up

It can seem stressful when your AC stops working properly, but it’s not the end of the world. A hard start kit can jump start your compressor. Any wiring problems you have can be fixed with the kit.

If you install it, you won’t have to replace your compressor, you’ll reduce wear and tear on the system, and save money on your electricity bill. Overall, it’s definitely an investment that benefits you in the long run.