Homeowner Articles Does My AC Need an Evaporator Coil Replacement or a New System

Whether you have an indoor or outdoor unit, we all rely on AC to escape the heat outdoors and provide quality cooling in our homes. But unfortunately, the more you lean on your AC unit, the likelier it is to wear down and break.

Some AC repair is as simple as one evaporator coil replacement, but other issues run deeper, and your entire AC might need to be replaced. But how can you tell what repair service you need?

We’ll examine what your AC evaporator coil (also called the ‘indoor coil’) does, how to tell when it’s broken, and whether you should be replacing your entire HVAC or only need one replacement part.

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What Do Evaporator Coils Even Do?

The evaporator coil takes the warm air from your home, uses stored-up refrigerant to drain its heat and moisture, and releases it into your home as crisp, cold air. In short, the evaporator coil allows your air conditioner to produce cool temperatures.

The AC evaporator coil is the most critical part of the entire unit, and it creates severe problems when it breaks that might make you think the whole AC system has shut down.

How Your Air Conditioner Regulates Temperature

A healthy air conditioner turns off and on according to a temperature sensor that monitors the temperature inside the house compared to the thermostat setting.

The AC will turn off if the inside temperature is cooler than the set temperature.

On hot days, the temperature will rise again as heat from the outside warms the air indoors, causing the air conditioner to turn on again until the temperature drops.

How to Tell When You Have a Broken Evaporator Coil

That brings us to the question on everybody’s mind: how can you tell whether you need an evaporator coil replacement or a brand new AC unit?

There are three tell-tale signs that your air conditioner needs a new evaporator coil, helping you avoid complete replacement or other repairs.

Inefficient Unit

Decreased cooling quality is the most common sign that your evaporator coil has worn down. Remember, the evaporator coil regulates temperature for the whole AC unit. So, if the coil completely breaks, the air conditioning system won’t cool the warm air it’s taking in and will instead cycle it on repeat.

Unfortunately, identifying broken evaporator coils based solely on the performance of your AC unit isn’t so simple. For example, a partially broken evaporator unit, or one that just needs more refrigerant, might still produce cold air without living up to its full potential

Additionally, most HVAC systems lose their effectiveness after a decade regardless of the condition of the evaporator coil. Luckily, an HVAC professional at Upstate Home Maintenance Services can examine your existing coil and get to the bottom of what’s causing your air conditioner woes.

Repeated Refrigerant Leaks

Since evaporator coils store your air conditioning’s refrigerant, any refrigerant leaks are likely a result of a busted evaporator coil. An AC without refrigerant plummets in effectiveness, so it’s essential to repair these issues quickly.

Visible Damage or Corrosion

There are no grey areas here; you need to replace your evaporator coil as soon as you spot cracks or corrosion buildup. Most HVAC systems have their evaporator coil in either the ductwork or furnace cabinet

It’s easier to see damage and corrosion with uncased coils, where the part is fully exposed once you remove the front from your air conditioner. However, some AC units have cased coils, and you will need to open the casing if you want to view the damage.

Why You Should Replace Just the Evaporator Coil

Now that you know when you’ll need to replace the evaporator coil in your AC, we can look closer at your two HVAC repair options. You can either purchase a new coil or replace your entire AC.

While both have their benefits, you can solve some critical short-term woes when you replace an evaporator coil rather than the whole unit.


The average AC evaporator coil replacement cost is far less than it takes to install a brand new AC unit but can still be a significant cost. Despite this air conditioner coil being the most integral and often most expensive part of the HVAC, it’s still only one part your technician needs to replace, compared to replacing an entire system.

Additionally, if your air conditioner is still on the manufacturer’s warranty, you might be able to get a replacement evaporator coil for free.

The general rule of thumb is if the repair cost is more than half of the replacement value, it’s worth considering a replacement.

Quicker, Less Dramatic Service

Most of us don’t want to wait longer than necessary to bring the cool air back. But you can save time relative to installing a brand new AC when you’re only replacing one part, like a condensate drain line or evaporator coil.

Additionally, if you’ve grown attached to your old AC or it has a home warranty you want to keep intact, a simple parts replacement ensures you get to keep the unit.

Why You Should Replace the Entire AC Unit

While evaporator coil replacement saves short-term money and stress, replacing the entire unit solves long-term issues. It will make your cooling more efficient, offer a more luxurious experience, and cut down on big-picture repair costs.

Syncing the Condenser Coil and Evaporator Coil

As necessary as the evaporator coil is for your HVAC system, it’s far from the only important part. The condenser coil (often called the outside coil, despite being located inside the AC) works with the evaporator coil to turn heat into cool air. And because the parts need to work together, manufacturers design them to match as well as possible.

So, if you carelessly spring for evaporator coil replacement without also updating the condenser coil, the two essential parts won’t match and won’t operate as harmoniously. And if the two parts aren’t identical in seasonal energy efficiency ratio (SEER) rating, age, or refrigerant content, it could create significant problems, including:

  • Lower efficiency and higher utility costs from running your AC longer
  • Inability to cool air
  • Shortened AC lifespan

Fewer Repairs

HVAC units have dozens of moving parts beyond the two essential AC coils, and your entire air conditioning system will suffer if any of them break. You have two options: keep replacing the coils and other critical pieces and pay repair labor costs every time something falters, or buy a new unit and get every part on the same lifespan.

Replacing an entire AC will cost more money in the short term, but the one-time, flat-rate payment can save you money in the long run from the additional costs of labor and maintenance. Because rather than needing to replace an old coil or a broken air handler in your dated HVAC unit, you’ll have a new system with every part built to last for a decade.

New, Feature-Rich Air Conditioners

Most houses have multiple decades-old ACs that combat the heat but aren’t as efficient or luxurious as most newer models.

Many new ACs are stronger than older machines, have energy-efficient cooling, more durable condenser coils, and automatically adjust their temperature based on your climate needs. But when you stick with your aging AC, you’re stuck with less efficient and less reliable temperature control.

Schedule Evaporator Coil Replacement Today

There’s no better team in South Carolina to repair your faulty AC than Upstate Home Maintenance Services. Not only are we experts on evaporator coils, but we know all AC parts like the back of our hand, from slab coils to the condensing unit.

We also offer professional AC installation and free estimates on our services, regardless of the unit size or brand. In addition to free estimates, our team now offers financing plans when you set up your new air conditioner through our team.

Call today for an AC evaporator coil replacement cost estimate or schedule a new HVAC installation.

This article was written by Morgan Loch

Owner of Upstate Home Maintenance Services LLC and Local HVAC Guru

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