A revealing service call: a loss of efficiency and a refrigerant leak
At AirGreen , we are regularly called upon to intervene in the Côte-des-Neiges–Notre-Dame-de-Grâce neighborhood, where several rental buildings and condominiums are equipped with Midea wall-mounted heat pumps . On that day, our team was contacted by a homeowner concerned about a significant drop in the performance of his air conditioning and heating system. His normally very efficient heat pump was no longer producing enough cold—a common sign of a refrigerant leak .
Initial diagnosis: pressure loss detected
Upon our arrival, our certified technician checked the refrigeration circuit . Thanks to our precision pressure gauges connected to the Midea external compressor, we noted an abnormally low pressure , confirming the suspicion of a leak. A slight oily deposit around the connections reinforced this diagnosis.
The customer noticed that the heat pump was running longer than usual without reaching the required temperature—a typical symptom of insufficient refrigerant charge.
Step 1: Locate the leak
We applied a foaming leak detection agent to the connections and valves of the outdoor compressor. The appearance of small bubbles revealed the source of the problem: a slightly loose connection at the service port. This type of leak, although minimal, gradually leads to a significant loss of energy efficiency and can, in the long term, damage the compressor.
Step 2: Repair and tighten the fittings
After recovering the residual refrigerant , our technician tightened the mechanical connections , cleaned the affected area and replaced the seals to prevent any recurrence. A complete vacuum of the system was then carried out to ensure the removal of internal moisture and impurities.
Step 3: Recharge with R410A refrigerant
With the system under stable vacuum, we carried out a controlled recharge with R410A , in accordance with Midea's specifications. The filling was carried out to the precise weight recommended by the manufacturer , which allows for optimal performance and increased longevity of the heat pump.
Using a calibrated refrigerant cylinder and electronic scales ensures accurate dosing, preventing overfilling that would be detrimental to performance.
Step 4: Performance testing and validation
Once the charge was complete, we restarted the system for a complete test in cooling and heating mode . The pressure and temperature measurements were perfect, confirming the return to normal.
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Low pressure : stable at 120 psi
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High pressure : balanced at 390 psi
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Temperature differential : conforms to Midea standards
The customer immediately noticed rapid and even cooling in his home.
Step 5: Preventive maintenance and advice
Before concluding the intervention, we took the time to explain to the client the importance of:
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Clean the interior filters regularly to ensure optimal air circulation.
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Have exterior fittings inspected every year , especially before the summer season.
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Avoid using the heat pump in heating mode at very low temperatures without automatic defrosting, in order to prevent ice from forming on the outdoor unit.
We have also enrolled this Midea unit in the AirGreen Preventative Maintenance Program , which offers comprehensive seasonal checkups and personalized monitoring to extend the life of HVAC systems.
Result: restored comfort and maximum efficiency
After this intervention, the Midea wall-mounted heat pump was back to its original efficiency. The system now blows powerful and stable cold air, with optimal energy efficiency . The relieved customer told us that he was worried about a complete replacement, but our methodical approach helped avoid significant costs.
This type of intervention perfectly illustrates AirGreen's rigor and precision in HVAC system diagnosis and repair in Montreal. Every step—from diagnosis to recharge—is carried out according to the strictest industry standards, ensuring long-lasting and reliable results.
Why choose AirGreen for your heat pump repairs in Montreal?
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Certified technicians specializing in Midea, Fujitsu, Gree, Sharp, and several other brands.
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Fast and professional service , available throughout the greater Montreal region, Laval, Longueuil, the North Shore and the South Shore.
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Advanced diagnostic tools and strict adherence to safety protocols.
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Commitment to customer satisfaction and sustainable systems performance.
AirGreen – Your trusted HVAC partner in Montreal and throughout Greater Montreal.
We repair, maintain and optimize your systems to ensure comfort, reliability and energy efficiency all year round.