visibilityHow to check
- Find where the condensate hose exits the building — usually a small white pipe running down the wall from behind the outdoor unit. With the mini-split running in cooling, you should see a steady trickle; no water there while it drips inside points to a blockage.
- Cut power to the unit at the breaker before doing anything near the indoor head or its wiring — never work on a wet, energized unit.
- Apply gentle suction at the outdoor end of the hose with a wet/dry vacuum (seal the connection with a rag). A slug of slime or water pulling free, followed by free flow, confirms a clogged line.
handymanHow to fix it
With the unit powered off, flush the condensate line clear: pull the blockage from the outdoor end with a wet/dry vacuum, then flush the line from the pan end with warm water (and a little diluted vinegar to slow regrowth) until it runs freely outside.
- Switch the mini-split off at the breaker and confirm it's dead before touching the indoor head or the pan — the electronics sit right next to the water.
- At the outdoor end of the condensate hose, seal a wet/dry vacuum over the opening with a rag and run it for a minute or two to pull the blockage out.
- From the indoor pan end, slowly pour warm water (a cup of 1:1 vinegar-and-water helps slow algae regrowth) and confirm it runs freely out the outdoor end.
- Restore power, run the unit in cooling, and watch for a steady outdoor drip and a dry pan indoors. If it still backs up, the line's slope or the pan may be the problem instead.
Clearing a condensate drain and cleaning filters are routine homeowner maintenance and permitted across Canada. By contrast, opening the sealed refrigerant circuit is restricted to certified technicians nationwide (federal ODS/halocarbon regulations plus provincial rules) — see the refrigerant cause's do_not_diy gate.