A night-time intervention to restore the comfort of a residence
At AirGreen , we know that a broken HVAC system can disrupt the peace and quiet of a home, especially on a cold evening when the heat pump is essential for comfort. This is exactly what we found during a service call in Sainte-Julie , on the South Shore of Montreal , for a Haier wall-mounted heat pump that refused to restart.
Diagnosis: Three outdoor units, one performance problem
On site, our team discovered a peculiar installation: three outdoor compressors , including a Haier model, a Gree and a Daikin , attached to the brick facade of a single-family home. The customer contacted us because one of the units—the Haier —was no longer blowing hot air, while the other two were operating normally.
First observations:
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The Haier unit was making a low but constant noise , with no fan starting.
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The interior control panel showed no error codes , but the interior temperature was dropping rapidly.
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The electrical connections appeared intact, but ice buildup was visible on the refrigerant line.
Step 1: Electrical Check and Compressor Control
We first inspected the power circuit . The voltage at the terminal block was stable (240 V), eliminating the possibility of a faulty circuit breaker. Upon testing the compressor and start capacitor , we found that the capacitor was weakened , preventing the compressor motor from starting properly.
Solution: Replacement of the 40 µF start capacitor , compatible with the Haier model.
After replacement, the compressor restarted correctly, but the outdoor fan remained inactive.
Step 2: Blocking the outdoor fan motor
Upon removing the protective grille, we discovered that the fan motor was blocked by a buildup of ice and dust at the base of the shaft. This obstruction prevented the motor from starting despite the correct tension.
After a thorough cleaning , defrosting with hot air and lubricating the shaft, the fan resumed normal operation.
Step 3: Check the pressure and defrost cycle
We then carried out a refrigerant pressure check . The measurements revealed a slight undercharge , probably caused by an old micro-leak. After topping up with R410A refrigerant , we tested the complete cycle in heating mode.
The automatic defrost cycle started normally, indicating that the electronic board was functioning correctly after the fan and compressor were restarted.
Results: restored comfort and optimized performance
After the intervention:
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The Haier unit returned to a blowing temperature of 42°C inside.
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The outside noise level has returned to normal.
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The client found stable comfort throughout the house, with no thermal imbalance between the areas served by the three units.
We advised the customer to perform six-monthly preventative maintenance , particularly before winter and summer, to prevent ice formation and damage to sensitive electrical components.
Key points of this HVAC repair in Sainte-Julie
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Repaired brand: Haier
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Machine type: Wall-mounted heat pump
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Initial problem: No heating, fan inactive, compressor silent
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Diagnosis: Faulty capacitor + fan blocked by ice
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Solution: Replace the capacitor, clean and lubricate the fan, top up the gas
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Result: Heating restored, optimal operation, satisfied customer
AirGreen expertise: fast, precise and sustainable
Every HVAC service call we handle is an opportunity to demonstrate our rigor and attention to detail. In Sainte-Julie , our team was able to respond quickly despite difficult nighttime conditions, ensuring full service recovery in less than two hours.
At AirGreen , we combine advanced technical diagnostics , original parts and professional service to extend the life of your equipment and ensure lasting comfort, whether you are in Montreal, Laval, Longueuil, on the North Shore or the South Shore .