In many Rosemont–La Petite-Patrie apartments, wall-mounted heat pumps (mini-splits) run almost continuously: providing supplemental heating in winter, air conditioning in summer, and dehumidification during seasonal changes. And when a simple symptom appears—like droplets and water accumulating under the indoor head —comfort can quickly turn into worry (plaster, paint, flooring, musty odors).
This intervention, carried out by our team at AirGreen , specifically concerned a Gree wall-mounted heat pump with a visible water leak at the level of the flap and the lower area of the indoor unit.
What the customer observed: a recurring “leak,” especially when it cooled down significantly.
The reported signs were typical:
-
Water beading under the indoor unit and along the fins/flap
-
Normal operation at first, then leakage after 30–60 minutes
-
Sometimes there is a sensation of less constant airflow, as if the device is "forcing" itself.
-
In some cases: a slight musty smell upon restarting
In the photo, drops and abnormal humidity can be clearly seen near the air outlet, which often points to a problem of poorly evacuated condensation (and not a “refrigerant leak”, which is much rarer on the indoor unit side).
Our AirGreen diagnosis: blocked drainage + fouling = condensate overflow
On a Gree wall-mounted heat pump , the water produced in cooling mode (and sometimes in dehumidification mode) must:
-
condense on the evaporator,
-
fall into the condensate drain,
-
to drain through the drain pipe to an outlet point.
When this path is obstructed, the water rises and eventually overflows , then comes out through the facade or the shutter.
During our inspection, we systematically checked:
-
Condition of the filters (often heavily loaded with fine dust in urban environments)
-
Condensate tray : water level, presence of deposits, biofilm
-
Drain slope and low points (counter-slope, subsidence, excessively tight bend)
-
Blocked drain (mud, dust + moisture, algae, particles)
-
Heat exchanger : fouling promotes excessive condensation and sprayed droplets
-
Airflow : fan, turbine, flaps, mode balance
Conclusion: The most consistent cause was a partially blocked drain , combined with fouling that increased condensation and disrupted normal flow.
The repair steps: complete cleaning, unclogging, flow test and return to service
Our approach always aims for a lasting result, not a temporary fix.
1) Securing and protecting surfaces
We protect the wall and floor (especially in condos/apartments), then we open the unit to access the bin and the sections to be cleaned without contaminating the environment.
2) Cleaning the filters and the heat exchanger
-
Cleaning the filters (and replacing them if damaged)
-
Degreasing/cleaning of the evaporator when necessary
-
Turbine check (often overlooked, but crucial to prevent splashing and moisture)
3) Drain unclogging and controlled rinsing
-
Drain pipe flushing and unclogging
-
Rinse the condensate tray to remove deposits and biofilm
-
Slope validation and slight correction if a low point creates a “water plug”
4) Functional testing under real-world conditions
We run the Gree wall-mounted heat pump long enough to reproduce the phenomenon:
-
Checking that the water drains quickly and regularly
-
Visual inspection: no drips on the shutter, no abnormal humidity
-
Confirmation of airflow and temperature stability
Result: comfort restored, device stabilized, and above all… no more water damage
After the procedure:
-
No more leaks or drips from the indoor unit
-
Condensate flow is smooth and constant.
-
More stable air, renewed sense of performance
-
Reassured customer: reduced risk of stains , gypsum swelling, paint peeling, and mold.
Why this problem often occurs in Montreal (and how to avoid it)
In Greater Montreal, we see this scenario very often, especially when:
-
The heat pump operates for a long time in dehumidification mode.
-
the filters are cleaned too rarely
-
The drain has a "just right" slope, but eventually becomes clogged and blocked.
Our simple (and effective) recommendations:
-
Clean the filters every 4–6 weeks during periods of heavy use.
-
Perform a complete maintenance check (including drain/basin) at least once a year
-
Watch for signs: musty smell, sloshing sound, dripping water, reduced airflow
AirGreen: Gree wall-mounted heat pump repair and maintenance in Rosemont–La Petite-Patrie
When an indoor unit starts leaking, it's not "just a little water." It's often a symptom of a clogged drain and a system operating under poor conditions. At AirGreen, we use a structured method: diagnosis, targeted cleaning, drainage correction, and load testing—to ensure the repair lasts.