Complete diagnosis and recommissioning of an aging wall-mounted device
At AirGreen , we are often called upon to work on air conditioning units that have been installed for more than ten or fifteen years. This was the case here, in a single-family home in Sainte-Julie , where a customer contacted us about a Sharp wall-mounted air conditioner that had stopped blowing cold air since the beginning of summer.
The indoor unit, installed above a sofa in the living room, showed signs of wear: slightly yellowed casing, dirty fins, and a slight vibrating noise each time it was started.
Initial assessment and diagnosis
Upon inspection, our certified technician noticed that the unit started up, but the outdoor compressor wouldn't start. After some testing, he identified a communication issue between the indoor unit's main board and the outdoor condenser board —a common defect on some Sharp models from the late 2000s.
The detailed analysis included:
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Testing internal thermal sensors .
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Checking the voltage signals on the communication cable.
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Visual inspection of the electronic board (swollen capacitors).
Measurements revealed an intermittent voltage anomaly , probably caused by a faulty card.
Technical intervention and repair
To fix the outage, our team took the following steps:
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Complete cleaning of the interior module with steam cleaning.
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Replacement of the main capacitor on the electronic board.
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Check and tighten inter-unit cable connections.
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Complete system reboot after calibration of the original remote control.
After the repair, the blowing temperature dropped to 10.4°C , confirming that the system was operating at full capacity again.
Recommended preventive maintenance
We also took advantage of the intervention to carry out a complete maintenance of the external condenser :
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Cleaning the fins under controlled pressure.
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Checking the refrigerant flow rate.
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Application of an anti-corrosion protector to copper fittings.
These operations make it possible to extend the lifespan of an aging system while optimizing its energy performance.
Results and customer follow-up
The customer immediately noticed the difference: the cold air returned quickly and the noise was gone. We recommended planning for a possible replacement within a few years, as the older Sharp models, although robust, are no longer compatible with the newer, more environmentally friendly and efficient R32 refrigerants.
Our technician suggested, when the time came, the installation of a modern wall-mounted heat pump from the Midea EVOX or Gree Lomo+ range, offering superior performance and significant energy savings, while meeting Hydro-Québec's grant criteria.
AirGreen expertise in Sainte-Julie and throughout Greater Montreal
Every AirGreen service call is handled with rigor: precise diagnosis, lasting repair and advice tailored to the customer's reality. Our team serves not only Sainte-Julie , but also all of Greater Montreal , including Laval, Longueuil, the South Shore and the North Shore .
At AirGreen , we put our HVAC expertise to work to ensure the comfort of Quebec homes — whether it's simple maintenance , complex repairs or a complete system replacement .