A winter service call for a snowbound outdoor unit
Quebec winters put a strain on residential HVAC systems . At AirGreen , we are regularly called upon during extreme cold weather for central heat pump breakdowns caused by ice or snow accumulating on outdoor units. This was the case in Blainville , where a homeowner contacted us after noticing that his Goodman heat pump was no longer producing heat.
Background and symptoms observed
The outdoor unit, installed on a raised metal stand, was literally covered in a thick layer of compacted snow . The customer reported to us:
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A complete shutdown of the compressor despite the heating request.
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Cold air blowing inside.
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No automatic defrost detected.
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A slight smell of overheating in the hot air duct.
At first glance, the outdoor condenser appeared to be in good condition, but the ventilation grilles were blocked , and the condensate drain pipe was frozen—two conditions conducive to a blockage of the thermodynamic cycle.
Detailed diagnosis by our HVAC technician
Our certified technician performed a complete inspection of the Goodman system . Here are the technical findings:
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Blockage of the external fan due to snow infiltrating the fins.
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Abnormally high refrigerant pressure , resulting from lack of heat exchange.
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Non-responsive defrost probe , preventing the automatic defrost cycle from initiating.
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Traces of internal frost on the liquid line , a sign of interrupted refrigerant flow.
We immediately shut down the heat pump to carry out a safety intervention.
Repair steps performed
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Complete defrosting of the unit using forced hot air, without the use of water to avoid thermal shock.
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Cleaning the fins and ventilation grilles with a biodegradable degreasing product.
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Checking and replacing the defrost sensor , responsible for the initial malfunction.
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Pressure and refrigeration cycle test to ensure proper compressor operation.
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Electrical check of the control relay and recalibration of the thermostat.
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Added an air deflector to limit snow accumulation during future storms.
Once the repair was completed, the system resumed normal operation: the heat pump efficiently alternated between heating and defrosting, and the interior temperature returned to 22°C in less than an hour.
Result: restored comfort and reinforced prevention
This intervention in Blainville clearly illustrates the importance of winter maintenance of central heat pumps . After our visit:
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The energy efficiency of the Goodman heat pump has been restored.
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Compressor noise has decreased by cleaning the fins.
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Automatic defrosting is working normally again.
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The customer has subscribed to our AirGreen preventive maintenance program , which includes two visits per year (spring and fall).
Winter Care Tips
To prevent this type of problem from occurring:
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Clear snow around the outdoor unit after each storm (minimum 30 cm clearance).
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Never completely cover the heat pump , except with a ventilated cover.
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Schedule a pre-seasonal inspection , especially if the system is more than five years old.
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Elevate the unit at least 30 cm off the ground to avoid direct contact with snow.
AirGreen expertise at your service on the North Shore
At AirGreen , we serve the North Shore of Montreal daily, including Blainville, Boisbriand, Sainte-Thérèse and Terrebonne . Our technicians specialize in Goodman, Trane, Lennox, Midea, Fujitsu and other recognized brands, ensuring fast and lasting interventions, even in extreme winter conditions.
Our commitment is simple: to diagnose accurately, repair efficiently, and optimize the performance of your HVAC system year-round .
Technical summary:
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Device type: Central heat pump
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Brand: Goodman
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Location: Blainville (North Shore)
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Problem: No longer heating, defective defrost sensor, snow accumulation
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Solution: Cleaning, replacing the probe, pressure testing, adding a deflector
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Result: Heating restored, efficiency and reliability restored
At AirGreen , we believe that a successful winter HVAC system starts with rigorous maintenance and rapid intervention at the first signs of trouble.