Rapid electrical intervention for a broken heat pump
At AirGreen , we know that a heat pump breakdown in the middle of the hot season can quickly become an emergency. This is exactly the case for this residential customer in Brossard , on the South Shore of Montreal , whose Gree wall-mounted heat pump suddenly stopped working after a short circuit.
1. Symptoms and Service Call
The customer noticed that the indoor unit was no longer responding to the remote control, and the outdoor unit remained completely inactive—no compressor sound, no fan rotation. Before calling us, he had tried checking the circuit breaker without success.
Upon our arrival, we immediately carried out a complete diagnosis of the electrical circuit to determine the origin of the fault.
2. Diagnosis: damaged communication wire
Upon opening the outdoor unit's connection box, we discovered a severed communication wire between the indoor and outdoor units. The cable had been excessively bent during a previous connection, causing an internal break in the conductor and a short circuit upon startup.
Our technicians confirmed the diagnosis using a multimeter and a continuity tester : the signal between terminals 2 and 3 was no longer circulating. This break prevented the main board from communicating with the indoor module, thus blocking the entire system.
3. Repair: Rewiring and professional insulation
We undertook a complete rewiring of the communication wire , respecting the Gree color code to avoid any polarity reversal. The cable was:
-
Stripped cleanly and reconnected to the screw terminals on the electronic board;
-
Welded and thermally insulated to ensure perfect conductivity;
-
Protected with heat shrink tubing and UV resistant insulating tape .
We then secured the wiring harness using cable ties to prevent any future mechanical stress.
4. Check and restart the system
Once the repair was complete, we turned the power back on and ran a full boot sequence :
-
The outside fan has started;
-
The Gree rotary compressor has restarted smoothly;
-
The indoor unit displayed the “Run” code confirming that communication was restored.
After 15 minutes of testing, the measured temperatures showed a difference of 11°C between suction and blowing , a sign of optimal performance.
5. Advice to the customer to prevent this type of breakdown
We explained to the customer that damaged or loose wiring is one of the most common causes of failure on wall-mounted heat pumps, especially after exterior work or movement of the exhaust duct.
Here are our recommendations to avoid the problem:
-
Avoid bending or pulling the cables connecting the two units;
-
Always turn off the power before handling the connection box;
-
Have annual preventative maintenance performed to check for any signs of wear on the wiring.
6. Result: communication restored, comfort regained
Thanks to our intervention, the client's Gree heat pump is now working perfectly. The heat exchange is stable, the electronic board is responding normally, and indoor comfort has been fully restored.
The client particularly appreciated the speed of our diagnosis and the quality of the rewiring—further proof of AirGreen's expertise in HVAC service in Brossard and throughout the greater metropolitan area.
7. Technical sheet of the intervention
-
Device Type: Gree 12,000 BTU Wall-Mounted Heat Pump
-
Problem: Cut communication cable / short circuit
-
Solution: Complete rewiring, insulation and securing of the harness
-
Result: System operational and communication restored
-
Location: Brossard, South Shore of Montreal
At AirGreen, we emphasize that every detail counts when it comes to electricity and HVAC performance. A single poorly insulated wire can cripple an entire heat pump. That's why we always prioritize meticulous, safe, and manufacturer-compliant repairs.