An aging device that refuses to start
During a service call in Longueuil , a customer contacted us about his Haier wall-mounted air conditioner , which had been installed for over ten years above an interior door frame. The unit, although robust, would no longer start despite several attempts with the remote control. No indicator light would come on, and no relay noise could be heard.
This type of failure is typical of older wall units , whose electronic circuits eventually suffer wear and tear over time, especially after long periods of winter inactivity.
Complete and methodical diagnosis
Upon our arrival, we carried out a detailed diagnosis following the AirGreen protocols:
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Control panel inspection : no voltage on the main board.
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Power supply check : correct voltage at input terminal.
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Thermal fuse test : internal fuse blown, preventing the compressor from starting.
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Visual inspection of components : presence of accumulated dust and oxidation on the printed circuit, sign of past condensation.
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Blower motor check : normal resistance, no damaged windings.
The diagnosis quickly confirmed that the main problem was the main control board , which had failed following a power surge.
Repair and recommissioning
Our technicians undertook the following repairs:
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Replacement of the thermal fuse with an equivalent Haier certified part.
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Thorough cleaning of the printed circuit board with a dielectric product to remove moisture and prevent false contacts.
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Repair the main starter relay using a compatible module recommended by the manufacturer.
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Continuity test and calibration of internal sensors .
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Full Restart : After a few minutes of testing, the unit resumed normal operation, blowing cool, stable air.
We also installed a small surge protection device directly on the power supply, an essential precaution in older buildings where electrical stability is not guaranteed.
Results and recommendations
After the intervention, the customer found a comfortable temperature and a fully functional unit . To extend the life of his Haier air conditioner, we recommended:
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a complete annual maintenance including cleaning of the filter and coil,
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to leave the device on standby during the winter rather than unplugging it completely,
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and regularly check the circuit breaker to avoid any electrical overload.
This type of refurbishment often extends the useful life by several years , while reducing energy consumption thanks to more stable operation.
AirGreen expertise
At AirGreen , we understand the challenges of repairing older wall-mounted air conditioners . Our team operates throughout Montreal, Laval, Longueuil, the North Shore, and the South Shore , diagnosing, repairing, and maintaining all major brands: Haier, Gree, Fujitsu, Sharp, Midea, Bosch, Lennox, Goodman, Trane, Zephyr , and more.
Thanks to our experience and attention to detail, we provide our customers with fast, durable service that complies with RBQ and CCQ standards, while maximizing the performance and safety of each HVAC system.