A service call on a flat roof in west Montreal
At AirGreen , we were recently called for an urgent repair of a Midea central heat pump installed on the roof of a commercial building in Sainte-Anne-de-Bellevue , in the west end of Montreal. The client, the owner of a small office building, had noticed that their HVAC system had not been providing adequate cooling for several days, despite the continuous operation of the outdoor fan.
On site, our team immediately recognized the typical configuration of a Midea central heat pump , a popular model for multi-zone buildings. The outdoor unit, installed on anti-vibration brackets above a flat roof, featured a distinctive blue propeller fan, while the compressor and electrical components were housed in an acoustically insulated compartment.
In-depth diagnosis: a revealing electrical reading
Our technicians began a full electrical diagnosis using a clamp multimeter to check the currents and voltages at the main terminals of the compressor and fan. The measurement showed 0.38 A at startup—an indication that the compressor was not receiving the full power required.
After ruling out a short circuit or motor overheating, we turned our attention to the main control board (PCB) and the power contactor , two components often stressed during summer heat waves. A continuity test confirmed that the contactor was not switching correctly, preventing power to the compressor despite active control.
Repair and replacement of the defective part
The contactor was removed and replaced with a compatible genuine Midea part. We then carried out a complete electrical check and tightened all connections, which are often subject to constant vibrations from the compressor.
Once the part was installed, reapplying power immediately restored compressor operation. Electrical readings stabilized around 5.8 A in continuous operation , within the manufacturer's standards for this model. The blue propeller fan resumed its smooth rotation, ensuring good heat dissipation through the condenser fins.
Condenser cleaning and efficiency optimization
Since the unit was installed on a flat roof exposed to the elements, we took advantage of the intervention to perform a complete cleaning of the condenser . The dust and debris accumulated between the fins were hindering the heat exchange, which had probably contributed to the overheating of the contactor.
A low-pressure cleaning with a biodegradable degreaser was performed, followed by a gentle rinse. The fan and motor were inspected to ensure that no blades were unbalanced or cracked.
Result: performance restored and customer reassured
After reassembly and final testing, the Midea heat pump returned to optimal operation. The supply air temperatures inside the offices quickly dropped, restoring the expected comfort.
We also provided the client with some preventative maintenance recommendations :
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Clean outdoor coils at least twice a year (spring and fall).
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Have the electrical connections and terminal tightness checked during each annual maintenance.
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Monitor for any voltage fluctuations or frequent circuit breaker tripping, often a sign of a relay problem.
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Maintain a clear space around the unit to prevent overheating.
AirGreen expertise at the service of Midea systems
This type of intervention perfectly illustrates our expertise in Midea HVAC system repair in Montreal and the metropolitan area. Thanks to our experience with central, wall-mounted, and multi-zone heat pumps , we are able to quickly identify the causes of breakdowns, whether electrical, mechanical, or refrigerant-related.
Whether it is for a sudden compressor failure , a faulty electronic card or a drop in energy performance , our certified technicians are equipped to intervene effectively, even on installations located on roofs like the one in Sainte-Anne-de-Bellevue.
AirGreen: the benchmark in HVAC repairs in Montreal, Laval, North Shore and South Shore
Every day, our teams travel throughout Montreal, Laval, Longueuil, the North Shore, and the South Shore to provide fast and reliable repairs to residential and commercial HVAC systems . Our mission is simple: to guarantee each customer lasting comfort, maximum efficiency, and peace of mind.
If your Midea heat pump or any other HVAC system is showing signs of weakness—unusual noise, loss of performance, or complete shutdown—don't wait for a complete breakdown. Call AirGreen , your trusted partner for heat pump repairs in Montreal and the surrounding area .