A Typical Service Call: When a Wall-Mounted Air Conditioner Stops Cooling Effectively
At AirGreen , we often receive calls during the summer months when customers notice that their wall-mounted air conditioner is no longer blowing cold air or is making an unusual noise. This was recently the case in Côte-des-Neiges , Montreal, where one of our customers contacted us about a breakdown of the Sharp air conditioner installed in his living room.
Upon our arrival, our technician noticed a classic setup: a Sharp wall-mounted air conditioner installed high above the television in a well-decorated and maintained space. This type of installation is common in condos and apartments in the area—unobtrusive, efficient, and perfectly suited to open-concept spaces.
Initial diagnosis: lack of maintenance and a faulty thermal sensor
The customer mentioned that the unit had started blowing lukewarm air , even when the remote control was set to 20°C. Additionally, a slight clicking noise was coming from the indoor fan.
Our technicians followed the following steps:
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Checked the filter : it was heavily clogged with dust, reducing airflow.
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Evaporator coil inspection : traces of ice were beginning to form, indicating a disturbed refrigeration cycle.
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Temperature sensor check : The thermistor (interior sensor) was giving an incorrect reading, preventing the compressor from regulating the temperature correctly.
These combined factors explained the loss of efficiency and the formation of ice in the system.
Intervention: complete cleaning and replacement of the sensor
After consulting with the customer, our team carried out an in-depth maintenance of the Sharp air conditioner:
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Complete cleaning of the evaporator coil using a non-corrosive solution suitable for wall-mounted units.
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Complete defrost to restore optimal airflow.
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Replacement of the faulty thermistor , an essential component for temperature control.
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Outdoor compressor test to confirm that the R-410A refrigerant charge remained within manufacturer specifications.
Once these steps were completed, we turned the unit back on: the customer immediately noticed a clear difference — the air was fresh, consistent, and quiet again .
Maintenance tips to extend the life of a Sharp wall-mounted air conditioner
Regular maintenance is key to avoiding similar breakdowns. At AirGreen, we recommend:
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Clean the filters every 2 to 3 months.
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Schedule professional maintenance at least once a year to check refrigerant pressure and sensor condition.
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Avoid obstructing air circulation around the indoor unit (for example, with furniture that is too close).
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Monitor for abnormal noises or variations in performance; these early signs may indicate impending failure.
Why call AirGreen in Montreal for your HVAC repairs?
Our certified technicians respond quickly throughout Greater Montreal , including Côte-des-Neiges , Laval , Longueuil , the North Shore and the South Shore . We are trained to diagnose and repair Sharp units, but also Fujitsu , Midea , Gree , Daikin , Mitsubishi and many others.
Every service call at AirGreen is based on three commitments:
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Complete transparency on costs and parts replaced.
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Precise and documented diagnosis for each breakdown.
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Compliance with energy performance standards and the comfort of our customers.
With this approach, we not only restore the proper functioning of your system, but also your peace of mind .
Final result: comfort restored and customer satisfied
At the end of our intervention, the Côte-des-Neiges client found optimal thermal comfort and a quiet and efficient Sharp air conditioner . This type of result perfectly illustrates our know-how: combining technical expertise and respect for residential comfort.
Whether your unit is experiencing unusual noise , insufficient cooling , a condensate leak or an electronic failure , our team is ready to respond quickly.
At AirGreen, we repair, maintain, and optimize all your HVAC systems to ensure your comfort, summer and winter.