A Revealing Service Call: When a Simple Lack of Maintenance Causes a Complete Breakdown
At AirGreen , we are regularly called to diagnose sudden breakdowns on wall-mounted air conditioners . This was recently the case in Sainte-Thérèse , on the North Shore of Montreal , where a customer contacted us after noticing that his Whirlpool wall unit was no longer blowing cold air despite the indicator light being on.
Our technician, dispatched to the site the same day, immediately recognized the model — a Whirlpool wall-mounted air conditioner approximately ten years old, still functional but requiring a thorough inspection .
Diagnosis: clogged filters and faulty electronic card
After removing the front cover, our team quickly noticed a significant buildup of dust on the filters and evaporator fins. This lack of maintenance was significantly reducing airflow, putting unnecessary strain on the compressor.
However, a second, more serious problem arose: the control board was displaying an intermittent error code, indicating an internal short circuit caused by humidity. This type of failure is common on older Whirlpool models exposed to significant humidity fluctuations—as is often the case when they are installed near a bathroom, as is the case here.
Technical intervention: repair and refurbishment of the wall unit
Our technicians have undertaken a complete refurbishment procedure :
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Thorough cleaning of the evaporator and internal fan using a biodegradable cleaner.
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Replacement of the main electronic card , calibrated with the new ambient temperature sensor.
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Checked the refrigerant pressure , which was slightly lower than the manufacturer's recommendations. An R410A recharge was therefore carried out.
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Complete system reset to ensure synchronization between the indoor unit and the outdoor compressor.
After a full test cycle, the air conditioner returned to optimal performance , blowing cool, constant air with an outlet temperature of 9°C after only 4 minutes of operation.
Result: comfort restored and preventive maintenance recommended
The customer immediately noticed the difference: the airflow, previously weak and noisy, was now quiet and powerful .
Before leaving the premises, our technician explained good maintenance practices :
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Clean the filters every 4 to 6 weeks during the summer season.
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Have the unit inspected once a year to prevent damage to the electronic board.
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Avoid continuous use when indoor humidity exceeds 70%, especially in areas near the bathroom.
AirGreen Expertise: Fast and Professional Service in Sainte-Thérèse
This case illustrates the importance of regular maintenance of residential HVAC systems .
At AirGreen , we offer a complete repair service for all major brands, including Whirlpool, Gree, Fujitsu, Midea, Sharp and Trane , throughout Montreal, Laval, Longueuil, on the North Shore and the South Shore .
Our interventions combine speed, transparency and technical precision , in order to extend the lifespan of your air conditioning systems while reducing the risk of breakdowns during a heatwave.
Is your wall-mounted air conditioner showing signs of weakness?
Do like this customer from Sainte-Thérèse: contact AirGreen , your trusted HVAC repair partner in Greater Montreal.
Our certified technicians travel quickly to diagnose, repair and optimize your wall systems, heat pumps and multi-zone units —regardless of make or model.