A service call in the heat of summer
On a particularly hot day in Plateau-Mont-Royal , a customer contacted us urgently: their LG wall-mounted heat pump was no longer producing cold air, despite the indoor unit operating normally. Installed above a patio door leading to a back deck, this configuration, typical of Montreal duplexes, required special attention—both for access to the outdoor unit and for accurate diagnosis.
Initial diagnosis: an active, but ineffective system
Upon our arrival, our AirGreen certified technicians carried out the essential checks:
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Blow-out temperature test , revealing a delta of only 2°C between ambient air and blown air — a clear sign of loss of cooling capacity.
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Inspection of the outdoor compressor : it started with a delay, producing a slight clicking noise characteristic of a capacitor failure .
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Visual inspection of the condensate drain : no obstruction detected.
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Refrigerant pressure control (R410A) : below the thresholds recommended by the manufacturer LG.
The verdict: a combination of a faulty capacitor and a minor leak in the suction line .
Intervention: replacement of the capacitor and recharging of the refrigeration circuit
The intervention was carried out in two phases:
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Replaced the start capacitor : LG compatible part, CSA certified. This operation immediately restored the compressor start sequence.
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Leak repair : located at the flare connection junction. After tightening and nitrogen pressure testing, no further leaks were detected.
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Complete system recharge with R410A fluid , according to factory specifications (990 g).
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Final thermal delta check : 9.5°C, in accordance with performance standards.
Results: restored comfort and optimized efficiency
In less than two hours, the LG wall-mounted heat pump was back to full performance. The customer, working from home, noticed a constant and quiet cooling of the room, with no temperature fluctuations, immediately after the repair.
Our team also has:
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Cleaned the internal filters .
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Checked the drain drainage .
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Reset the automatic temperature control mode .
This complete upgrade guarantees stable performance for seasons to come.
AirGreen Tips: Maintain to Prevent
At AirGreen, we always emphasize that annual preventative maintenance is the key to the longevity of an HVAC system.
In this specific case, the capacitor failure could have been anticipated by:
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A complete electrical check during the last service.
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A refrigerant pressure test at the start of the season.
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Regular cleaning of the outdoor unit , which is particularly exposed to dust and urban debris.
Professional annual maintenance not only helps prevent breakdowns, but also reduces energy consumption by up to 20% .
Why choose AirGreen for your HVAC repairs in Montreal
Our interventions are carried out exclusively by RBQ and CCQ certified technicians , trained to diagnose and repair all major brands: LG, Sharp, Fujitsu, Midea, Gree, Daikin, Bosch, and more .
We serve Montreal, Laval, Longueuil, the North Shore and the South Shore , with priority given to urgent calls during heat waves.
Each AirGreen repair includes:
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A complete intervention report .
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Before/after performance tests.
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Personalized maintenance recommendations .
A heat pump ready for years of comfort
Thanks to this LG wall-mounted heat pump repair in Plateau-Mont-Royal , the customer now benefits from a high-performance, energy-efficient and quiet system.
A typical AirGreen intervention: fast, rigorous and lasting.