Understanding common central heat pump failures: AirGreen’s expertise at your service
At AirGreen, we know how essential a properly functioning central heat pump is to ensure your year-round indoor comfort, whether you live in Montreal, Laval, Longueuil, on the North Shore or the South Shore. Unfortunately, like any mechanical system, a central heat pump can show signs of weakness or break down entirely. And these issues tend to happen at the worst times — right in the middle of winter or during a scorching heat wave — making fast and effective intervention absolutely crucial.
In this article, we share our on-the-ground experience and know-how to explain in detail five common central heat pump issues, along with practical solutions we implement during our service calls across Greater Montreal.
1. The system no longer blows hot or cold air
Technical diagnosis:
One of the most frequent service calls we get at AirGreen concerns a lack of heating or cooling. This can stem from several causes: a faulty thermostat, a damaged electronic control board, a compressor issue, or an insufficient refrigerant level.
Real case – Laval:
A residential client in the Chomedey area contacted us when their Bosch BOVA 36 central heat pump stopped blowing hot air right in the middle of January. Upon inspection, our technician diagnosed a slow refrigerant leak (R-410A) and a defective temperature sensor. We performed a complete refill, sealed the leak, and replaced the sensor. The system was fully operational again in less than 3 hours.
AirGreen solution:
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Full inspection of the refrigerant circuit
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Pressure testing to detect leaks
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Recharge with the appropriate refrigerant (R-410A, R-32 or R-454B depending on the model)
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Thermostat check and calibration
2. The central heat pump makes unusual noises
Technical diagnosis:
Excessive or unusual noise coming from the indoor or outdoor unit may indicate an unbalanced fan, worn motor bearings, or even a damaged compressor.
Real case – Longueuil:
In a single-family home in Old Longueuil, a Lennox ML14XP1 central heat pump was making a persistent metallic noise. After inspection, our team discovered that the indoor blower wheel was loose. Replacing the part and tightening the supports immediately resolved the issue.
AirGreen solution:
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Inspection of fans and motors
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Replacement of worn parts
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Checking supports and mechanical alignment
3. Frost on the outdoor unit during winter
Technical diagnosis:
Ice buildup on the outdoor unit during winter is often related to a faulty defrost cycle, a malfunctioning temperature sensor, or insufficient airflow.
Real case – North Shore (Blainville):
A commercial client using a Trane XR15 central heat pump to heat a 3,000 sq. ft. space reported that the entire outdoor unit was covered in ice. The diagnosis revealed a defective defrost relay and an indoor air filter completely clogged. A prompt intervention allowed us to manually defrost the unit, replace the relay, and swap out the filter.
AirGreen solution:
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Defrost cycle verification
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Cleaning of filters and coils
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Replacement of sensors or control relays
4. The unit doesn’t start at all
Technical diagnosis:
A completely inactive unit may point to a major electrical issue: a tripped breaker, a fried control board, a blown fuse, or motor failure.
Real case – Montreal (Rosemont):
A duplex owner contacted us when their Gree Flexx 36,000 BTU central heat pump failed to start during a heat wave in July. The control panel was blank and there was no sign of operation. After investigation, we found a thermal fuse had blown in the outdoor electrical box. We replaced it and restarted the system without complications.
AirGreen solution:
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Inspection of electrical panel and wiring
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Component continuity testing
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Replacement of faulty fuses or boards
5. Water leaks inside the house
Technical diagnosis:
Water dripping from the indoor unit may result from a clogged drain, a cracked drain pan, or excess condensation due to improper settings.
Real case – Brossard:
In a South Shore home equipped with a Goodman GSZC18 central heat pump, water had damaged the basement ceiling. Our inspection showed that the condensate drain was blocked by debris and the condensate pump hadn’t been serviced in years. After a full cleaning and replacing the pump, the issue was resolved.
AirGreen solution:
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Cleaning of drains and drain pans
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Condensate pump testing
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Inspection of condensation level and flow
Practical tips to prevent these issues
At AirGreen, we strongly recommend regular HVAC maintenance, which is essential to extending the life of your central heat pump and preventing costly breakdowns:
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Annual professional maintenance, including cleaning, calibration, and performance testing
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Regular replacement of filters
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Refrigerant level check
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Inspection of electrical and mechanical components
We offer custom HVAC maintenance plans for all types of installations across Montreal, Laval, Longueuil, the North Shore, and the South Shore.
Why choose AirGreen when your central heat pump breaks down?
With several hundred successful interventions each year, our certified team stands out thanks to:
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Quick and accurate diagnostics
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Intervention within 48 hours in most cases
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Direct access to replacement parts from brands such as Bosch, Fujitsu, Gree, Goodman, Trane, Lennox, Zephyr, and more
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Complete territorial coverage: Montreal, Laval, Longueuil, North Shore, South Shore
Our service areas for HVAC installation, repair and maintenance
Whether you're a homeowner in Saint-Jérôme, a building owner in Verdun, or a business manager in Boucherville, our teams are ready to intervene quickly for any central heat pump issue.
We cover:
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Montreal (Ahuntsic, Villeray, Rosemont, TMR, etc.)
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Laval (Chomedey, Duvernay, Sainte-Dorothée)
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South Shore (Longueuil, Brossard, Saint-Lambert, Sainte-Julie)
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North Shore (Terrebonne, Repentigny, Blainville, Mirabel)