My Pioneer Mini Split is not draining appropriately and leaks water from somewhere that it is not supposed to, what could be the problem?

There are only a few reasons as to why a Pioneer wall-mounted indoor unit could be leaking water. The most common reason is that the drain tube, which is an insulated tube on the rear side of the indoor unit is cracked, clogged, or not at a continuous downward pitch.

Check the state of the drain hose, and any extensions that were attached to it. Ensure that it can drain freely by conducting a drainage test. You can do this by opening the front panel, removing any filters, and pouring water over the coils. 

Then you can check whether this water is exiting from the point of drain as it is supposed to.

Another set of possible causes:

• The indoor unit is not level
• The drain pan is cracked or damaged
• The drain outlet port is exposed (most models have drain ports on both sides, where the unused one stays plugged by a stopper)
• The drain pan needed to be cleaned. If it is filled with debris or dust, and is preventing water from draining, then you can pour a 50/50 mixture of water and white vinegar into the drain pan to unblock it, or use specialized cleaner tablets

If your unit passes the drainage test, but drips water from time to time, then your issue is not plumbing/drain related but can likely be attributing to either:

• If water drips from the front louver where air blows out: Make sure that any air flaps or louvers are not in a closed position, where they are cutting of airflow. This will lead to a buildup of condensation and thus, dripping. Ensure to remove any airflow restrictions by manipulating the air louvers and flaps such that they are allowing air to blow out freely.
• If water drips as a result of excessive ice/frost forming on the coils: Potentially the system is low on refrigerant. This causes a buildup of icing and frost on the coils, to the point where you can see ice completely blocking your view of the coil. This ice then melts and leads to water dripping off of the unit, which is ultimately a symptom of a bigger problem at hand. Check the operating pressure of the system and recharge to spec if needed.

On top of all these possible causes, it is always best practice to ensure that your filters, coil, and blower wheel are clean and clear. Otherwise, it can limit performance of the equipment and potentially lead to unintended consequences such as water dripping or leakage.