Repair of a Gree wall-mounted heat pump in Outremont

Targeted intervention for a complex electronic breakdown

At AirGreen , we were recently called to Outremont , a typical Montreal residential duplex, to diagnose a Gree wall-mounted heat pump that had completely shut down. The outdoor unit, installed near a brick wall and partially under a wooden deck, was no longer responding to commands from the indoor unit. The owner had already tried to restart the system, without success.

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Initial diagnosis: electronic failure and a stationary fan

Upon our arrival, our certified technician noticed several clues:

• The compressor would not start .

• The outdoor fan remained stationary , even in test mode.

• The unit made no relay noise or electrical clicking , indicating a faulty power supply or control board .

A quick disassembly of the upper case confirmed the presence of a defective inverter board . The metal surface of the board, visible in the photo, showed traces of oxidation and deposits related to condensation accumulated over time.

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Step 1: Complete electrical check

Before any manipulation, we cut off the power to the system to ensure a safe intervention. The following tests were then carried out:

• Input voltage measurement (240 V) : correct.

• Internal power circuit continuity test : compliant.

• Measurement of low voltage (DC) coming out of the card: absent.

These measurements confirmed that the main inverter board was indeed the source of the fault.

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Step 2: Board Disassembly and Component Inspection

The Gree card was carefully removed for inspection. We found:

• A blackened power resistor .

• A weakened weld on the fan control section.

• Slight traces of moisture near the main connector.

This type of damage is common in installations located too close to the ground or exposed to moisture , as was the case here under the deck.

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Step 3: Cleaning the condenser and preparing for return to service

Taking advantage of the clear access, we carried out a complete cleaning of the condenser :

• Removing leaves and debris stuck at the base.

• Degreasing the fins using a specialized biodegradable product.

• Checking the condensate drain flow and the condition of the refrigerant capillary .

This preventative cleaning is essential to avoid overheating of the compressor once the card is replaced.

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Step 4: Inverter board replacement and calibration

We installed an original Gree electronic card , supplied by our authorized warehouse. After connection:

• All connections were tightened and insulated with heat shrink sleeves.

• A soft start test was performed to calibrate the inverter frequency.

• The system restarted smoothly, with a stable cooling cycle and no sound anomalies.

The final measurements showed:

• Indoor outlet air temperature : 9°C.

• Operating pressure : stable at 255 psi.

• Power consumption : 1.15 A in nominal mode.

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Step 5: Customer Advice and Preventive Maintenance

We recommended to the client:

• Raise the condenser slightly to avoid stagnant humidity.

• To carry out an annual cleaning of the fins .

• Protect the unit with a ventilated shelter , without obstructing the air flow.

These precautions will help extend the life of the electronic card and improve system stability.

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Result: restored performance and increased reliability

After repairs, the Gree wall-mounted heat pump returned to its original efficiency. The owner noted an immediate improvement in indoor comfort and a reduction in outdoor noise.
This intervention perfectly illustrates AirGreen's ability to quickly diagnose complex electronic faults , while ensuring optimal maintenance to prevent future problems.

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Technical details of the intervention

• Brand : Gree

• Device type : Wall-mounted heat pump (mini-split)

• Location : Outremont (Montreal)

• Problem detected : electronic failure – defective inverter board

• Solution : Card replacement, complete cleaning, recalibration

• Result : stable operation, smooth restart, restored efficiency

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At AirGreen , every service call is handled with rigor and expertise, whether for a complex diagnosis or routine maintenance . We operate throughout Montreal, Laval, Longueuil, the North Shore and the South Shore to ensure the comfort and performance of your HVAC systems throughout the year.