Generally a unit could run for around 40 minutes after starting up before a defrost can be initiated. From there defrosts could occur approximately every 40 minutes if the temperature hasn’t risen.

What causes a mini split to freeze up?

The most common one is that your refrigerant levels are low. The reason a lack of refrigerant can cause this ice buildup is due to what refrigerant itself is. … Another reason that ice can develop in your air conditioner is because the air is not flowing fast enough through the system and across the coils.

Is it normal for a mini split to defrost?

Your mini split unit can defrost more often if you have gone through an especially bad winter or after a storm. This is normal. However, if the unit tries to defrost even when the weather is somewhat warmer, that’s a problem.