An intervention at height for restored comfort
At AirGreen , we are regularly called upon to carry out complex repairs requiring work at heights, often on multi-story residential buildings. This was the case in Lachine , where a homeowner contacted us about a breakdown of a Gree wall-mounted heat pump whose outdoor unit, fixed to the third floor, was no longer starting.
Context and initial findings
The customer had noticed for a few days that his heat pump was no longer blowing hot or cold air , even when the wall control seemed to be working correctly. Upon arriving on site, our technicians performed a visual inspection of the outdoor unit using a lifting platform , a necessary approach to ensure the safety and accuracy of the work.
The outdoor wall unit, a Gree 18,000 BTU model , was showing signs of aging:
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fins partially clogged with dust and debris,
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traces of oil around the refrigeration connection,
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external fan blocked by a deformation of the grille,
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and electronic board covered with moisture deposits.
Complete diagnosis: a combined failure
After initial checks, our technicians noted a double failure :
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Refrigerant leak at a solder joint on the discharge pipe.
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Faulty electronic power board , preventing the compressor from starting.
These two problems explained the complete failure of the system. Without refrigerant, the compressor could not maintain the minimum operating pressure, and the faulty card blocked the control of the main relay.
Step 1: Repair the leak and recharge the refrigeration circuit
We first proceeded to repair the leak :
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cutting out the damaged copper segment,
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silver re-soldering to ensure watertightness,
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nitrogen test under 300 psi for 30 minutes,
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complete vacuuming of the system to remove all moisture,
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and recharge with R410A according to the quantity prescribed by Gree (1.25 kg).
The system was then successfully repressurized, with no further leaks detected.
Step 2: Replacing the electronic card
The main electronic board , responsible for managing the compressor and the fan, showed traces of oxidation and burning at the level of a relay.
We replaced this board with an original Gree part , then reprogrammed the internal initialization module.
Once the new card was installed, the compressor started working again immediately.
Step 3: Checks and complete maintenance
Taking advantage of the nacelle, we carried out a complete preventive maintenance of the unit:
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steam cleaning of the fins,
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fan motor lubrication,
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tightening of electrical connections,
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checking the condensation drain,
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temperature sensor and defrost probe check.
We also measured the discharge pressure and temperature , confirming optimal performance.
Result: performance and security restored
After these interventions, the Gree heat pump was working at full capacity again, providing a stable and quiet flow of hot air. The client was impressed by the speed and precision of our work, especially considering the complexity of the access.
We advised him:
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a complete annual maintenance before each heating season,
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and a preventive leak check every two years to avoid refrigerant losses.
AirGreen Expertise: Safety, Precision and Reliability
This type of intervention perfectly illustrates our technical know-how and our high safety standards .
Each member of our team is trained to work with cradles and safety harnesses in order to work on installations located at height.
At AirGreen , we combine expertise, cutting-edge equipment and rigor to guarantee:
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lasting repairs ,
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precise diagnoses ,
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and fast service everywhere in Montreal, Laval, on the North Shore and the South Shore .
Thanks to this approach, the Gree wall-mounted heat pump in Lachine has regained its full performance, ensuring comfort and peace of mind for its owner.