A revealing service call: an outdoor heat pump exposed to the elements
At AirGreen , we were recently called to Sainte-Dorothée, in Laval , to repair an LG wall-mounted heat pump that was no longer working optimally. The customer had noticed that his outdoor unit was making an abnormal noise and that the heating was no longer keeping up despite the still mild outside temperature.
Upon arrival, we found a relatively new installation but directly exposed to the elements—a common situation for compressors installed on the rear facade, without shelter or sufficient clearance around the unit.
Technical diagnosis: warning signs of an overloaded compressor
Our technician performed a complete check of the refrigeration cycle . The refrigerant pressures showed an imbalance: the high pressure was too high and the low pressure too low. This indicated either a partial lack of refrigerant or a restriction in the electronic expansion valve .
We then inspected:
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The condenser : slightly clogged with dust and plant debris.
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Refrigeration pipes : no apparent leaks, but the outer sheaths showed signs of wear.
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Electrical connections : minor traces of oxidation on a starter relay.
After completing these checks, we determined that the problem was caused by insufficient airflow through the condenser coil, which was causing the compressor to overheat and trip .
Repair steps: cleaning, recalibration and prevention
Our technicians have undertaken the following actions:
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Deep cleaning of the condenser using a biodegradable degreaser, ensuring optimal heat exchange.
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Replacement of the starter relay showing signs of corrosion.
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Checking and adjusting the R-410A refrigerant charge according to LG manufacturer specifications.
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Complete performance test : measurement of evaporation and condensation temperatures, control of indoor/outdoor delta T.
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Installation of an anti-vibration mount and a partial deflector , to protect the compressor from snow projections and improve air circulation.
Result: restored performance and comfort regained
After our intervention, the LG heat pump returned to optimal performance . The customer immediately noticed a stable recovery of heating and a significant reduction in outside noise.
This visit illustrates the importance of:
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Regular preventative maintenance , especially before winter.
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Sufficient clearance around the compressor (at least 30 cm at the rear and 60 cm at the front).
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Good condition of the ducts and insulation , often neglected but essential to avoid condensation and heat loss.
What this intervention demonstrates
Even a high-performance LG wall-mounted heat pump can lose efficiency if the outdoor unit is left exposed without maintenance. Thanks to our HVAC expertise, we were able to quickly identify the real cause of the problem—not an electronic fault, but an imbalance related to the unit's ventilation and environment .
At AirGreen, we believe that a thorough diagnosis and preventive intervention are always better than an emergency repair.
AirGreen: your HVAC expert in Laval and throughout Greater Montreal
Our certified technicians work every week in Montreal, Laval, Longueuil, on the North Shore and the South Shore , for repairs to heat pumps, wall-mounted air conditioners, MultiZone systems and central units .
Each service call is treated with the same rigor:
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Complete device diagnosis.
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Sustainable and brand-tailored solutions.
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Transparency and personalized maintenance advice.
If you notice abnormal noise, decreased performance, or ice buildup , don't wait for a complete breakdown —contact AirGreen for a quick, professional inspection.