Winter intervention on a frozen heat pump
At AirGreen , our teams travel summer and winter to ensure the comfort of homes across Montreal's South Shore . This service call came from a customer in Sainte-Julie , concerned that their Midea wall-mounted heat pump stopped heating as soon as the temperature dropped below -10°C. The unit seemed to operate intermittently, with a dull noise and an abnormal buildup of ice on the outdoor unit.
Complete diagnosis: a typical problem during frost
Upon arrival, our technician noticed a thick layer of ice under the outdoor condenser. The fan was spinning slowly, and the defrost cycles were clearly ineffective. After a detailed inspection, the diagnosis was made:
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Defective defrost sensor , preventing the control from starting the defrost cycle.
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Badly inclined wall bracket , causing water to stagnate and freeze quickly at the base of the device.
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Partially clogged defrost drain , aggravating ice formation.
These combined problems significantly reduced the system's efficiency and threatened to damage the compressor in the long term.
System repair and realignment
The intervention began by partially dismantling the front panel and disconnecting the defrost sensor . After checking with the probe, the part displayed inconsistent resistance - proof of its failure. We replaced it with an original Midea sensor, recalibrated for the R32 range installed at the customer's site.
Next, our technician readjusted the wall bracket by correcting its inclination: the slope was now compliant with standards, promoting the natural flow of condensate to the outside. To prevent any return of frost, we also:
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Cleaned the drain ,
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Checked the R32 refrigerant charge ,
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Tested the automatic defrost mode ,
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Applied a thin layer of anti-corrosion protective coating to the condenser tray.
Results after recommissioning
Once the adjustments were completed, we turned the system back on and observed several complete cycles. Results:
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Hot air outlet temperature : 42°C after 5 minutes of operation.
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Automatic defrosting normally starts after 45 minutes, without abnormal noise.
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Smooth water flow under the tray, a sign that the drainage was working perfectly.
The customer immediately noticed the difference: the heat pump regained its full heating power, without excessive noise or vibration.
AirGreen expertise in extreme conditions
Quebec winters put HVAC systems to the test. A poorly installed or maintained heat pump can quickly accumulate ice, reducing its performance and increasing energy consumption.
At AirGreen , we insist on:
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The correct inclination of the wall brackets ,
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Sufficient clearance around the compressor (minimum 30 cm at the rear and 60 cm at the front),
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Preventive replacement of sensors when temperature differences appear,
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And cleaning the defrost drain before each winter.
These simple checks help prevent the majority of winter breakdowns encountered on Midea, Gree, Fujitsu or Sharp wall-mounted heat pumps installed on the South Shore and in Greater Montreal.
Comfort restored, even in the snow
At the end of the intervention, the Midea heat pump was running smoothly, ensuring consistent heat inside despite the deep snow outside. The customer, impressed by the precision of the work and the speed of the diagnosis, decided to subscribe to our AirGreen Winter+ maintenance program , which includes a complete annual check-up before each cold season.
This repair in Sainte-Julie perfectly illustrates our commitment: combining technical expertise, rigorous installation and personalized service so that each customer benefits from lasting comfort, even in the most extreme temperatures.
In summary
Thanks to a targeted intervention on the defrost sensor, the drainage and the wall bracket, AirGreen restored the performance of a Midea heat pump in the middle of winter in Sainte-Julie . A successful operation that once again demonstrates our HVAC expertise on the South Shore of Montreal .