When winter puts wall-mounted heat pumps to the test
At AirGreen , we know how essential an efficient wall-mounted heat pump is to weather Montreal's harsh winters. This service call, received on a frigid January morning, concerned a Gree wall-mounted heat pump installed on the roof of a duplex in the Rosemont–La Petite-Patrie neighborhood. The customer reported a complete shutdown of the heating system after a night of snowstorms.
An outdoor unit covered in ice
Upon arrival, we noticed the heart of the problem: the Gree Inverter outdoor unit was completely covered in snow and frost . This accumulation prevented the fan from rotating and blocked the airflow essential for heat exchange. A common situation in winter, especially when the unit is not protected by a suitable awning or lacks clearance around it.
We immediately have:
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Cut off the power supply to secure the intervention area.
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Manually removed snow and ice using non-metallic tools to avoid damaging the fins.
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Inspected the automatic compressor defrost , suspecting a faulty defrost sensor or control relay .
In-depth diagnostics and performance testing
Once released, the heat pump was subjected to a series of tests:
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Checking the defrost mode in the electronic control.
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Thermistor (coil temperature sensor) check.
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Measurement of refrigerant circuit pressures using a digital pressure gauge.
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Observation of the inverter cycle to ensure that the compressor modulation correctly responded to the thermal demand.
As a result, the defrost sensor was no longer properly detecting the coil temperature, preventing the system from triggering its automatic defrost cycle.
Corrective intervention and prevention
We replaced the faulty sensor with a genuine Gree part and restarted the system to validate operation. After 15 minutes of observation, the heat pump automatically switched to defrost mode , eliminating the remaining ice residue and returning to optimal performance.
To prevent a recurrence, we also have:
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Recommended the installation of a protective canopy over the outdoor unit.
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Optimized the drainage angle of the wall bracket to promote the flow of condensate.
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Reminded the customer of the importance of a minimum clearance of 30 cm around the unit for adequate air circulation.
Result: comfort and efficiency restored
Within minutes of restarting, the interior temperature had risen from 18°C to 22°C, with a steady and quiet flow of hot air. The relieved customer noted the speed of our response despite the harsh winter conditions.
Why choose AirGreen for your Gree heat pump repairs?
Our certified technicians work on all Gree heat pump models, whether wall-mounted, multi-zone, or central systems. Our expertise covers:
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Advanced electronic diagnostics (cards, probes, relays, sensors).
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Checking the refrigerant R-32 or R-410A .
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Controlled defrosting and prevention of ice build-up.
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Energy performance settings to optimize consumption.
Best practices for protecting your heat pump in winter
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Clean snow around the outdoor unit after each storm.
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Never turn off the heat pump during periods of intense cold: the automatic defrost mode depends on regular cycles.
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Schedule a fall preventive inspection with AirGreen to calibrate your sensors and check pressures.
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Avoid shelters that are too closed and block ventilation.
Conclusion
This Gree wall-mounted heat pump repair in Rosemont–La Petite-Patrie perfectly illustrates our mission: to guarantee comfort and reliability, even in the most demanding climatic conditions.
At AirGreen , each intervention combines rigorous diagnosis , lasting repair and preventive advice so that your HVAC system remains efficient throughout the year, in Montreal , Laval , on the North Shore and the South Shore .