An urgent service call to a downtown Montreal office
At AirGreen , we often receive calls from offices located in the heart of Montreal where air conditioning plays a vital role in daily comfort. On this day, we were contacted by a client located in the Ville-Marie area, in a modern office building with large south-facing windows. Their Comfortmaker wall-mounted air conditioner , installed a few years ago, refused to blow cold air even though the outdoor compressor was running.
The diagnosis: an internal problem linked to the temperature probe
Upon arriving on site, our technician first checked the external signs:
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The indoor unit displayed an operating light, but no noticeable airflow.
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No motor noise, which indicated the internal fan was not starting.
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The customer mentioned that the day before, the device had been working intermittently.
After opening the hood, we carried out a series of tests:
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Checking the supply voltage to the electronic board.
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Fan motor continuity measurement — normal result.
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Analysis of the return temperature probe: abnormal resistance and unstable variation.
The cause of the failure was identified: the indoor temperature sensor was sending incorrect information to the control board, blocking the fan from starting.
A quick and clean repair
We immediately replaced the probe with an original Comfortmaker part from our mobile inventory. After installation and power up:
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The fan started up again.
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The airflow was constant and quiet.
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The blowing temperature quickly dropped to 12°C , demonstrating optimal performance.
To ensure long-lasting efficiency, our technician also cleaned the air filter , inspected the condensate drain , and tested communication between the indoor and outdoor boards .
The importance of regular maintenance in urban areas
Devices located in city centers, especially in buildings with large glass surfaces, are subject to intensive operating cycles. Fine dust and rapid temperature fluctuations put a strain on internal sensors and electronic circuits.
At AirGreen, we recommend that building managers:
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Schedule biannual preventative maintenance (spring and fall).
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Check filters and drainage regularly.
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Observe for signs of failure (quiet fan, lukewarm air, flashing lights).
Result: comfort regained and efficiency restored
Once the repair was completed, the office temperature stabilized in less than 15 minutes. The relieved customer regained a comfortable environment for his employees without having to replace the entire unit.
This type of intervention demonstrates the importance of a precise and methodical diagnosis . At AirGreen, we always favor repair before replacement , when it is technically and economically justified.
A word about the Comfortmaker brand
Comfortmaker systems are renowned for their robustness and stable performance, but like any electronic device, they require maintenance. Replacing a simple temperature sensor can extend its lifespan by several years. Our technicians are trained to work on this brand as well as on Fujitsu, Midea, Gree, Goodman, Sharp, and Trane , throughout Montreal, Laval, Longueuil, on the North Shore and the South Shore .
In conclusion
This intervention in Ville-Marie perfectly illustrates our commitment: to react quickly, diagnose accurately, and restore life to systems essential to daily comfort.
Thanks to our expertise in HVAC repair , we help individuals and businesses in Greater Montreal extend the life of their equipment while ensuring optimal energy efficiency.