Air Conditioner Delayed Start – Why And How To Fix

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Getting down to the bottom of what's wrong with an HVAC system can feel impossible sometimes. Have you noticed that your AC has a delayed start and don't know what to do? Well, we've done extensive research into this topic and have the answer for you. Let's get into it.

The most common cause for a delayed air conditioner is that the thermostat connected to it is experiencing a power shortage. Considering that the AC relies on its thermostat greatly, this can affect how well it cools your home and how often it clicks on.

That said, you want to make sure and test your thermostat and have it fixed if necessary, typically by having a C-wire installed.

As we begin, we will cover all things air conditioners and discuss how to get yours working again. Whether this is a constant struggle in your home or has recently started, we're here to offer some help. With that said, let's jump right into this post!

A min split air conditioning unit mounted on the wooden paneling wall, Air Conditioner Delayed Start - Why And How To Fix

Why Is My Air Conditioner Delayed?

As we covered, the main reason an AC unit has a delayed start is because of an issue with its thermostat. Typically, this will happen if your thermostat isn't getting enough power, causing a delayed start to the air conditioning.

An up-close photo of an air conditioning unit

Furthermore, some experts claim that a delayed AC could be due to an old capacitor. As time goes on, the electronics in your air conditioner's thermostat will wear out, which can cause problems.

Luckily, you can usually fix this by having an electrician come out and install a C-wire, so there is no need to worry. However, if your thermostat has more extensive damage due to moisture or fire, you could need to replace the whole thing.

How Long Should It Take For AC To Kick In?

An AC unit should start cooling immediately after adjusting the thermostat. That said, if you turn up the air, you can expect your system to turn off.

Most often, air conditioners will need a minute to reboot after a power outage or reset, so in those cases, expect to wait closer to 30 minutes.

Again, this shouldn't ever be more than 30 minutes, so if your air conditioner won't turn on, there's likely something wrong with the thermostat.

How Do You Fix A Delayed Air Conditioner?

For those struggling with a delayed AC, there are ways to fix this. Most commonly, you want to install either a C-wire or an adapter. As we mentioned, these will help with any power loss during the start-up process.

If you have a newer thermostat system, like the Nest, you will also want to check its lithium-ion battery. Although more technologically advanced, systems like Google Nest can wear out and require a new battery.

Furthermore, it's also good to have an electrician look at your system to ensure there isn't a bigger underlying problem. Older systems tend to wear out, affecting other components of your air conditioner.

Can I Replace My Air Conditioner Thermostat Myself?

As long as you understand the process of replacing a thermostat, it's certainly possible to repair it yourself. We only recommend this for those comfortable with electric components and wiring, so if you aren't 100% sure of what you're doing, call a professional instead.

Of course, saving money on the installing or replacement process may sound enticing, but you can do plenty of damage if you aren't careful.

Most importantly, if you don't wire your thermostat correctly, this can result in a major fire. You could also hurt your AC system, so paying for an electrician may be worth it.

How Much Does It Cost To Repair An AC Thermostat?

Man adjusting the temperature of the thermostat

Although this will vary, you can usually expect to pay between $110 and $304 to repair a thermostat. Again, these are simply averages, so it's possible to spend much more depending on the size of your home.

According to Home Advisor, exact thermostat repair costs range from about $50 to $500, so this can be a relatively cheap thing to do. However, if you have an older system and the wiring is damaged, this will require more time, which means higher labor costs.

On top of that, newer thermostat systems with digital displays advertise being cheaper and easier to install, so that may be worth considering.

How Do I Know If My AC Thermostat Is Broken?

The first step to repairing or replacing an AC thermostat is figuring out what's wrong. Luckily, a few warning signs to watch out for will tell you if your thermostat is broken. These include:

  • Your thermostat has no power or is unresponsive.
  • Your air conditioning won't turn off/runs constantly.
  • The temperature of your room doesn't match the thermostat setting.

Of course, these are just a few easy-to-detect problems, so it's best to have someone inspect your system if you think something's wrong. AC thermostats will often break over time, so you should be able to catch on and make the needed repairs before it's too late.

How Long Does An AC Thermostat Typically Last?

In general, an air conditioner thermostat should last about ten years. The lifespan of a thermostat will greatly depend on the quality, model, and type of thermostat you have, so this is different for everyone.

As we said, as thermostats age, it's expected to see problems with your air conditioner. This can include a delayed start, constant running, and even a complete shutdown.

According to Energy Savers, the most common signs of aging for a thermostat are dust accumulation, wiring issues, and rusting. So even if you take great care of your AC system, it's inevitable that your thermostat will eventually fail.

On the other hand, many air conditioning systems will come with a warranty, so if you have one, you should be covered.

How Often Should You Change Your AC Thermostat?

It's not necessary to change an air conditioner thermostat more than every 8-10 years. As we covered above, the average lifespan of an AC thermostat is roughly a decade, so this is a good replacement timeline to follow.

However, if you notice problems early on with your air conditioner, there could be a defect in the thermostat, which will require a replacement. The most common manufacturer defects include faulty sensors, digital screens, and even bad wiring.

You want to make sure and have these issues handled ASAP, as they can cause higher energy usage, electric bill increases, and damage to your AC unit.

How Fast Should The AC Cool Down A House?

A green living area incoporated with an orange sofa, wooden flooring and a mini split air conditioning unit

Generally, an air conditioner should be able to a moderate, four-bedroom home by ten degrees Fahrenheit in three hours. Of course, this can be slightly different depending on the weather outside, the layout of your house, and the age of your AC system.

The speed of an air conditioning unit will also depend on its size. For example, if you have a moderately sized unit and your home is 2,000 square feet, it should be able to cool the space down within a few hours.

On the other hand, you could wait much longer if you have a medium-sized AC unit and a massive home. Luckily, HVAC specialists will give you size recommendations for your home's AC system while buying/building it, so you aren't on your own.

How Long Should It Take To Cool A House From 80 To 75 Degrees?

If it's warm outside and you need to cool down fast, expect your AC to bring down the temperature from 80 to 75 degrees in about 4-6 hours. As we said, the size, age, and model of AC unit you have can impact cool times.

In general, it's a better idea to keep your home at a constant temperature, rather than wait until it gets too hot. Waiting until your house reaches 80 degrees can put unneeded pressure on the air conditioner, so try to avoid this.

Why Won't My Air Conditioner Turn Off?

A mini split air conditioning unit mounted on top of the window

If your air conditioner doesn't turn off, a few things could be to blame. First, you want to check the evaporator coils in your system. If they are frozen, this will explain why your AC won't stop running.

Next, a clogged or dirty air filter can cause an AC unit to continue running. To fix this, make sure and replace your current filter with a new, clean one. This should solve the problem.

Another cause for constant running is a bad electrical relay switch. You will need to call a professional to fix this, so keep that in mind. Furthermore, your thermostat may have gone bad, so many things cause this.

To Wrap It All Up

A min split air conditioning unit mounted on the wooden paneling wall

Whether you recently bought a new AC system or have an older one, knowing how it works is essential. From what we found, a delayed system could mean something is wrong with the thermostat.

To fix this, you want to make sure your thermostat is wired correctly, and all parts are in good working condition. Furthermore, a delayed air conditioner could mean your unit is dirty or clogged, so take a good look at your unit.

Regardless, don't be afraid to schedule an appointment with an HVAC specialist if you suspect something's wrong with your air conditioner. Again, don't repair your thermostat unless you're 100% comfortable with the wiring, as this can be dangerous.

Made it to the end? Check out these helpful related HVAC posts below!

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