What happens
Unintended air leakage, surface condensation or thawing produces water outside the normal disposal condition.
Typical symptoms
Dripping persists after drain cleaning, particularly in humid conditions.
Checks that distinguish this cause
Locate where water forms and evaluate seals, approved insulation, coil condition and actual humidity. Separate water produced in the intended pan from water forming on cabinet or accessory surfaces.
What can look similar
A concealed obstruction can still cause backup only after long operation.
Repair direction
Correct the established insulation, sealing or underlying airflow/icing condition.
Verify the repair
Verify dry unintended surfaces and stable condensate removal during a sustained representative run.
Equipment-specific limits
Determine cabinet orientation, operating mode and accessory presence first. Condensate evaporators, nebulizers and other disposal systems are optional and have their own instructions; do not assume every AIO has one.
Practice this diagnosis
This cause is a reference topic; it does not yet have a dedicated simulated call. Browse the practice board.
References and applicability
Original HVACSim explanations with manufacturer and instrument-maker references for further reading. These resources support the subject; their model-specific examples are not specifications for every system.
- INNOVA (formerly Ephoca): AIO technical resourcesChoose cabinet style, generation and accessories. Installation, maintenance and troubleshooting documents are separate.
- Olimpia Splendid: Unico product literatureArchitecture and product selection; obtain the actual Unico installation and service manual for diagnostic limits.
Editorial review: 2026-09-29. Verify the current manual for the installed model.