When it’s hot outside, it might seem unlikely that your air conditioner (AC) unit would freeze up. But if you notice an air conditioner frozen pipe outside, don’t panic — it’s not actually all that uncommon. When your AC is working hard to cool your house in the summer, a number of issues can cause it to freeze up.
Reasons Your AC Unit Freezes in the Summer
Are you seeing ice starting to form on your AC unit? One of these causes could be to blame.
The Air Filter Is Dirty
The air filter is an important part of your AC. If you haven’t replaced it in a while, it could be covered in a thick layer of dust. This prevents air from moving freely through the system and reduces the amount of warm air that flows over the coil. The coil gets colder and colder, and eventually its temperature drops below freezing.
At this point, you might notice an air conditioner pipe frozen outside. Let it go too long, and your unit might freeze over. Dirty air filters can also cause problems such as short cycling and higher energy bills.
It’s Low on Refrigerant
Your AC unit uses refrigerant to absorb heat from the air inside your home. It’s contained in a closed-loop system to ensure the AC can run efficiently. When there’s a leak, the refrigerant level drops. This reduces pressure in the system and causes the refrigerant’s temperature to drop significantly. The moisture near the lines freezes, creating visible ice on the exterior.
Something’s Blocking the Air Vents
Because airflow is important for proper AC operation, anything that restricts it can cause problems, including blocked air vents inside your house. For example, you might not realize that a set of heavy drapes is covering a vent or your child’s toy box is preventing air from moving effectively. Like a dirty filter, restricted airflow can cause the coil to get too cold and freeze.
The Coils Are Dirty
You probably don’t pay much attention to your AC coils, but over time, they can accumulate a lot of dirt. That thick layer of grime prevents the coils from absorbing heat inside your house and releasing it outdoors, which means the system can’t work properly. Without efficient heat transfer, the temperature drops and the lines freeze. This is when you might start to see ice on the AC unit outside or inside.
The Drainage Lines Are Clogged or Damaged
If your AC unit has drain lines, a clog or blockage can lead to freezing. When the water can’t drain properly, it backs up into the unit until it comes into contact with the cold pipes. The moisture freezes around the refrigerant lines, and you may see an air conditioner frozen pipe outside.
In Michigan, drain lines often get clogged during cottonwood season and any time storms carry in debris. The small particles can accumulate and back up the system.
The Fan or Thermostat Is Faulty
As temperatures rise, your AC system works harder to cool your home. This increase in operation tends to escalate small issues, which can create a range of symptoms, including the AC unit freezing up in the summer.
Two common problems include a faulty thermostat and a broken fan. When the thermostat isn’t working correctly, it can’t regulate the system. And if the fan is having trouble, it can affect airflow and freeze the lines.
What to Do About an Air Conditioner Frozen Pipe Outside
As with many common appliance issues, you might not realize anything is wrong until you see an AC unit frozen pipe outside.
Follow these steps if your AC is covered in a layer of ice:
- Turn off the AC: Find your thermostat and turn off the cooling system.
- Let the AC defrost: Give the ice on your AC unit a few hours to melt. You can turn on the fan setting to speed up the process.
- Look for the issue: Check the air filter and drain line, make sure your air vents aren’t blocked and look for buildup on the coils. If you can’t find an obvious problem, consider calling an HVAC technician for an emergency repair; you could be dealing with a more serious issue, such as a refrigerant leak or a broken thermostat.
- Start up the system: Once you make a fix, such as installing a new air filter, restart your AC.
If your AC continues to freeze even after you’ve tried DIY repairs, it’s important to call a repair technician. Ignoring the problem could cause more extensive damage. A pro can find the cause, fix the problem and get your home back to a comfortable temperature.
A freezing air conditioner can make for an uncomfortable summer, especially if you live in the Metro Detroit area. If you’re not sure what’s causing the problem, give us a call at Great Dane to schedule an inspection. Our experienced team can help you find the right solution so you can enjoy the warm weather.
