A faulty power module: an invisible, but critical failure
At AirGreen , we often receive calls from customers whose Gree wall-mounted heat pump suddenly stops heating or cooling, without any noise or error lights. This is exactly what happened in this residence in the Sainte-Rose neighborhood of Laval . The customer noticed that the indoor unit appeared to be operating normally—fan active, remote control responsive—but the air blown remained at room temperature.
First observation: a silent compressor
Our technician arrived on site and first observed the behavior of the outdoor condenser . No compressor noise, no vibration, but the electronic board seemed to be powered on. By checking the power cables and the communication with the indoor unit, everything seemed to be in order. We therefore suspected a problem with the power module (IPM) , located in the main condenser board.
Step 1: Opening and inspecting the electronic board
The Gree outdoor unit was carefully opened, exposing its control compartment . As is often the case with this type of failure, the electronic components— inductors , capacitors , and diode bridges —showed signs of excessive heat.
Our checks revealed:
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traces of oxidation on two connectors,
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a slightly browned reel ,
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and an inoperative thermal fuse .
This type of failure is typical of voltage variations experienced during thunderstorms or frequent restarts.
Step 2: Continuity tests and confirmed diagnosis
Using a multimeter and an IGBT tester, the technician confirmed that two transistors in the IPM module were permanently open —a problem preventing the compressor from starting.
This fault cuts the engine's power supply, blocking starting without generating any visible error code inside.
Step 3: IPM Module Replacement and Complete Cleaning
AirGreen maintains a complete inventory of Gree circuit boards for the most common models. We replaced the power module, cleaned the compartment with compressed air, and re-did the electrical connections with dielectric gel to prevent future oxidation.
Once the new card was installed, the compressor restarted immediately. We measured:
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a stable discharge pressure ,
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an amperage in accordance with the manufacturer's manual ,
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and a blowing temperature of 11°C in air conditioning mode – proof of optimal performance.
Step 4: System Calibration and Maintenance Tips
Before closing the intervention, we recalibrated the outside temperature sensor and tested the defrost cycle. The system was then returned to automatic mode.
Our recommendations to the client:
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Install a surge protector on the heat pump's main outlet.
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Avoid frequent restarts during periods of high heat.
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Schedule an annual inspection to clean the boards and check the capacitors.
These simple measures can extend the life of a wall-mounted heat pump's electronics by up to 12 years or more .
Result: comfort restored and efficiency restored
As soon as the intervention was completed, the home was cool again within minutes. The client noticed an immediate difference: the indoor temperature dropped from 27°C to 22°C in less than 30 minutes.
We also checked the airflow in the indoor unit, confirming that communication between the two modules was fully restored.
AirGreen expertise: a guarantee of reliability
At AirGreen, our technicians are experts in repairing Gree wall-mounted heat pumps , whether it's electronic modules, compressors, sensors or fans . We operate daily in Montreal, Laval, Longueuil, on the North Shore and the South Shore , for accurate diagnostics and long-lasting repairs.
This case in Sainte-Rose perfectly illustrates our approach: combining rigorous technical analysis , genuine parts , and transparent service . The result? A high-performance heat pump, a satisfied customer, and a system ready for many years of reliable comfort.
In conclusion: this intervention demonstrates that the power board of a Gree heat pump, although invisible to the user, is a critical element of overall performance. Thanks to in-depth expertise and locally available parts, AirGreen guarantees a rapid return to comfort, regardless of the breakdown encountered.