What would cause a mini split to freeze up?

Your mini split has frozen solid.

You might find this more plausible if it was the middle of winter, but it isn’t. It’s summertime and quite hot outside, so why is your mini split system a block of ice?

There are several reasons why a mini split will freeze up like this, actually. In today’s post, we’ll go over them all.

Slowed Airflow

How fast is the air moving through your ductless mini split system?

If it’s not speedy enough, then your mini split can freeze up.

What happens is the evaporator in cooling mode, within the mini split will decrease in temperature to such a degree that they’ll freeze.

Typically, a mini split’s coils are suspended in a state that’s about freezing but not quite. That’s because the coils consistently receive air that crosses over them whenever your mini split is operating.

At that temperature, even when the moisture in the air condenses on the coils, they don’t freeze, and the water can continue traveling to a collection pan.

Once the coils decrease in temperature even further, that moisture and condensation will indeed allow the coils to freeze.

So why has this happened? Well, the impediment to airflow is usually caused by dirty components between the coil and the fins.

If you haven’t had your mini split technician out to the house in at least six months or even longer than that, then it’s no wonder these components have gotten dirty. Your mini split needs maintenance.

Your mini split system’s fan might also be having issues, so that’s slowing down the flow of air and allowing the coils to freeze.

Low Refrigerant

Another reason that a mini split can freeze up is due to low refrigerant.

Although refrigerant is nicknamed coolant, it’s used to both heat and cool your home via your ductless mini split system, albeit in different ways.

The refrigerant is supposed to pull heat from the coils and send that warm air to the next coil to produce cool air in your home all summer long.

However, the lack of refrigerant halts this process. Without a heat transfer, the environment within the mini split can get so cold that ice can accumulate.

So what do you do once you realize that your ductless mini split system has frozen over? Well, you can’t ignore the issue.

The ice probably won’t melt on its own no matter how hot it is outside since the issue is all internal. Trying to run a frozen mini split can damage the components more and possibly even break the system.

What you should do instead is call your mini split technician. They’ll break up the ice, top off coolant levels, and fix any issues that are prohibiting airflow so your mini split works like a charm.