A ductless mini split system is one of the most efficient and comfortable ways to heat and cool a home. But like any HVAC system, proper installation is key to long-term reliability. One of the most overlooked yet critical steps during installation is making sure the indoor wall-mounted unit is perfectly level.

Even a slight tilt in the wall unit can cause major issues — including water leaking from the front fins or bottom of the unit.

Here’s Why Level Installation Matters

Every ductless wall unit has an internal drain pan and a condensate drain line that carry moisture safely out of the system. When warm air passes over the cold evaporator coil, condensation naturally forms. That water is supposed to collect in the pan and drain through the tubing to the outside or into a pump.

However, if the wall unit isn’t mounted level:

• Condensation will pool unevenly inside the pan.
• The water may not reach the drain outlet properly.
• Once the pan fills up on one side, it can overflow into the blower section.
• This often causes water to drip out of the fins, front cover, or bottom casing of the unit.