Symptoms
- Water dripping from the indoor unit
- Wet spot on the wall or floor below the unit
- May coincide with heavy cooling use in humid weather
Likely causes
- CommonClogged condensate drain lineThe small drain hose can accumulate algae and sediment just like a central AC's drain line.
- CommonDrain hose kinked or improperly slopedA hose that doesn't slope continuously downward can trap water and overflow.
- PossibleDirty air filter causing excess condensation buildupReduced airflow can cause more moisture to collect on the coil than the drain can handle.
- Less commonImproper installation angle of the indoor unitIf the unit wasn't mounted with a slight rearward tilt, condensate can drain toward the room instead of the drain.
What to do
- Turn off the mini-split to stop adding more water while you investigate.
- Clean the washable air filter, since a dirty one can worsen condensation issues.
- Locate where the condensate drain hose exits the wall outside and check for a steady drip when the system runs.
- Use a wet/dry shop vac at the outside end to try to pull free any clog in the line.
- Check that the hose has a continuous downward slope with no low spots trapping water.
- If the leak continues after clearing the drain, have a technician check the installation angle and coil.
Tools and parts
- Wet/dry shop vac
When to call a pro
Call an HVAC technician if clearing the drain line doesn't stop the leak; the installation angle or internal drain pan may need attention.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.