Understanding common failures of a central heat pump: AirGreen’s expertise at the service of your comfort
At AirGreen, we understand how essential a central heat pump in good condition is to ensure your thermal comfort year-round, 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. It is often at the most critical moments — in the heart of winter or during a heatwave — that these breakdowns occur, making quick and effective intervention crucial.
In this article, we share our field experience and expertise to explain in detail five common problems with central heat pumps, as well as our practical solutions that we implement during our interventions throughout Greater Montreal.
1. The system no longer blows warm or cold air
Technical diagnosis:
One of the most common service calls we receive at AirGreen concerns a lack of heating or air conditioning. This can be caused by several issues: a faulty thermostat, a damaged electronic control board, a compressor problem, or an insufficient refrigerant level.
Real case – Laval:
A residential client in the Chomedey neighborhood contacted us after their Bosch BOVA 36 central heat pump stopped blowing warm air in the middle of January. After inspection, our technician diagnosed a slow leak of R-410A refrigerant and a faulty temperature sensor. We performed a full recharge, sealed the leak, and replaced the sensor. The system was back in service in less than 3 hours.
AirGreen Solution:
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Complete inspection of the refrigeration circuit
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Pressure test 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 abnormal noise
Technical diagnosis:
An excessive or unusual noise coming from the indoor or outdoor unit can 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 fan turbine was loose. Replacing the part and tightening the supports immediately fixed the problem.
AirGreen Solution:
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Inspecting fans and motors
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Replacing worn parts
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Checking supports and mechanical alignment
3. Frost on the outdoor unit in winter
Technical diagnosis:
An ice buildup on the outdoor unit during winter is often related to a faulty defrost circuit, 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 3000 sq ft space reported a block of ice completely covering the outdoor unit. Diagnosis revealed a faulty defrost relay and a fully saturated indoor air filter. A quick intervention allowed manual defrosting of the unit, replacement of the relay, and changing the filter.
AirGreen Solution:
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Verification of the defrost cycle
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Cleaning of filters and coils
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Replacement of sensors or control relays
4. The unit does not start at all
Technical diagnosis:
A completely inert unit can indicate a major electrical problem: tripped breaker, burnt circuit board, damaged fuse, or motor failure.
Real case – Montreal (Rosemont):
A duplex owner called us after his Gree Flexx 36,000 BTU central heat pump failed to activate during a heat wave in July. The control panel was black and no activity was detected. After checking, it was a blown thermal fuse in the outdoor connection box. We replaced it and restarted the system without complications.
AirGreen Solution:
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Inspection of the electrical panel and connections
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Continuity test of components
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Replacement of fuses or faulty circuit boards
5. Water leaks inside the house
Technical diagnosis:
Water flowing from the indoor unit can come from a clogged drain, a cracked recovery pan, or a problem of excessive condensation due to incorrect settings.
Real case – Brossard:
In a South Shore home equipped with a Goodman GSZC18 central heat pump, water leakage damaged the basement ceiling. Our inspection showed that the condensate drain was blocked by debris and the lift pump had not been maintained for several years. After a complete cleaning and pump replacement, the problem was resolved.
AirGreen Solution:
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Cleaning of drains and recovery pans
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Lift pump test
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Inspection of condensate level and flow
Practical tips to prevent these breakdowns
At AirGreen, we emphasize the importance of regular HVAC maintenance, essential to extend the lifespan of your central heat pump and avoid costly breakdowns:
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Professional annual maintenance including cleaning, calibration, performance testing
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Periodic filter replacement
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Checking refrigerant levels
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Inspection of electrical and mechanical components
We offer customized HVAC maintenance contracts for all types of installations in Montreal, Laval, Longueuil, on the North Shore and South Shore.
Why call AirGreen in case of a central heat pump breakdown?
With several hundred successful interventions each year, our certified team stands out for:
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A quick and accurate diagnosis
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An intervention within 48 hours in most cases
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Direct access to replacement parts from brands like Bosch, Fujitsu, Gree, Goodman, Trane, Lennox, Zephyr, and others
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Complete coverage of the territory: Montreal, Laval, Longueuil, North Shore, South Shore
Our service areas for HVAC installation, repair, and maintenance
Whether you are a homeowner in Saint-Jérôme, a building owner in Verdun, or a business manager in Boucherville, our teams are ready to respond quickly to any central heat pump issue.
We cover, among others:
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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)