It may seem downright preposterous, but believe it or not it is possible for your air conditioner to freeze while running in the middle of a blistering summer afternoon. When we say this to customers, sometimes they can’t believe their ears—how is it possible for your air conditioner to freeze when it’s more than 100 degrees outside and seemingly no amount of air conditioning can cool your home off enough? In this blog, we’ll explain why this can happen, and provide you with four steps you should follow right away should you discover that your air conditioner has frozen.
What Causes a Frozen Air Conditioner?
To simplify it immensely, a frozen air conditioner is the consequence of two different issues in your air conditioner: restricted airflow, and a dirty condenser coil. Over time, different parts of your air conditioner will accumulate dust and debris that is pulled through your system. The vast majority of this debris is filtered out by your air filter, but air filters are not perfect, and we also find that the majority of people do not change them often enough. When an air filter does fill up, it can’t allow as much air to pass through it, resulting in restricted air flow through your air conditioner as a whole.
However, this restriction does more than just waste energy and make your air conditioner feel weak and ineffective—it also prevents much-needed heat transfer from happening. The air that passes over your condenser coil transfers its heat into the coil itself, which performs two key functions of your air conditioner. Primarily, this cools and dries the air that flows through your air conditioner so it can be sent to go cool your home, but it also transfers heat into the refrigerant—something needed to keep your air conditioner flowing smoothly. When this heat transfer does not occur, your refrigerant does not warm up, and that’s when you’re at risk for a freeze.
When air passes over your condenser coil, water vapor in the air instantly reverts to a liquid form through a process known as condensation. In fact, it’s the same principle that causes a thin film of moisture to develop on the side of an ice-cold glass of water. Under normal circumstances, this water will simply drip off of your coil and flow away through your condensation drain. However, when the refrigerant in your condenser coil can’t absorb heat from the air passing over it in order to bring the temperature up, the coil itself becomes so cold that the water vapor hitting it turns to liquid and then immediately freezes solid. This process repeats itself until it eventually snowballs to the point where your entire air conditioner has frozen over and your air conditioner stops working altogether as a result.
Follow These Steps to Fix the Problem
Here are four things you should do right away if you discover that your air conditioner has frozen over.
- First, shut off your air conditioner right away. While many air conditioners have sophisticated sensors that will shut your system off automatically if it senses a problem like this, you should always make sure you flip your system off at your thermostat. You do not want your air conditioner to turn on again and continue trying to run while the coil is still frozen.
- Second, you’ll want to check your air filter. If it’s dirty, replace it right away. Do this before turning your system back on. You’ll want clean, unrestricted airflow as soon as it becomes safe to turn your air conditioner back on again.
- Third, you’ll want to call a professional to have your system checked. In some cases, a freeze can actually damage important components, and could be a symptom that you have a different issue that needs to be addressed. You’ll also want to have your technician clean your condenser coil, as this will remove a lot of the dust and debris on the coil that actively prevented heat transfer, thus contributing to the system freezing up.
- Finally, you can begin to melt the ice in your condenser coil system by using a low-temperature heat source like a hair dryer. Do not use a solder flow heat gun or something that can reach excessively high temperatures, as these can damage important components. However, using a hair dryer should allow you to melt the ice quicker, and that means you’ll be able to safely turn your system back on faster. Make sure you keep an eye on your drain pan and be certain that any runoff water is draining away properly—it’s not uncommon for condensate drains to clog up, and when they do they could spill water all over your home.
If your air conditioner has frozen over this summer, call All Pro Plumbing, Heating, Air & Electrical at (909) 253-0664 now and we’ll get it running again as soon as possible!