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Réparation de thermopompes Goodman sur toit-terrasse dans Le Sud-Ouest (Montréal)
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Goodman rooftop heat pump repair in Southwest Montreal

On some Montreal residential buildings—especially renovated condos and multiplexes— outdoor heat pump units are often installed on the roof, grouped on rails, with refrigerant lines and electrical connections neatly organized. This is precisely the context of this AirGreen project in the Southwest borough : a set of Goodman wall-mounted (mini-split) heat pumps installed on a roof, serving several indoor units.

Our mission: to restore the system quickly, cleanly, and above all permanently, without a temporary “patch”.

Context: a multi-unit rooftop installation, typical of urban condos

Visually, one can recognize an installation designed for stability and maintenance:

  • Goodman outdoor units aligned on a metal structure (rails)

  • Anti-vibration pads/pads under the supports to limit noise transmission within the building

  • Accessible electrical disconnections on each unit (for safety and maintenance)

  • Grouping of connections (pipes and cables) to prevent friction and wind damage

This type of environment (exposed roof) is excellent for condenser ventilation… but it also creates real constraints: direct sunlight, wind, dust, temperature variations, and sometimes micro-vibrations which eventually wear out certain connections.

Reported symptoms: unstable comfort and uneven performance

The customer described a very common problem with grouped mini-split systems:

  • One area was cooling/heating less effectively than the others.

  • Irregular starts (short cycles) on a unit

  • Abnormal noise /vibration noticeable at times

  • Overall yield decreases, especially during peak periods (heat or cold).

In an apartment building, this kind of situation quickly becomes frustrating: some residents are decent, others are not — and we mistakenly believe that “all the machines are broken.” Often, this is not the case.

AirGreen diagnosis: methodical, quick, without assumptions

With a wall-mounted heat pump (mini-split), you don't "guess". You measure, you confirm, then you repair.

Our diagnosis was carried out in 4 stages:

  1. Complete visual inspection

    • condition of the external coils

    • pipe contact points (vibrations/friction)

    • Wiring, terminal blocks, protective devices, drainage

  2. Electrical check

    • power supply and voltage stability

    • tightening of connections

    • inspection of disconnection boxes

  3. Functional checks

    • Inverter start-up, modulation, and reactions

    • behavior under load (heating/cooling)

    • comparison between units (relative performance)

  4. Refrigeration circuit tests

    • consistency of pressures/response time

    • looking for signs of insufficient load or restriction

    • leak testing if any doubt arises

What we found: two typical causes of rooftop installations

1) Fouling + reduced heat exchange

On rooftops, fine dust, urban particles, and certain seasonal deposits can reduce heat exchange. As a result, the machine works harder, modulates poorly, and comfort becomes inconsistent.

2) Micro-vibrations and connections to be secured

Even with solid supports, a grouped installation can create slight vibrations which, over time, influence:

  • certain electrical connections

  • the holding of the collars/connecting fasteners

  • the passage of cables and pipes (risk of friction)

Repair: cleaning, securing, restoring optimal performance

We carried out a complete restoration, adapted to this type of roof:

  • Technical cleaning of the coils (without damaging the fins)

  • Slight straightening of affected fin areas (when required)

  • Re-fixing and securing the connections (avoiding friction and fatigue)

  • Electrical checks and controlled tightening of terminal blocks

  • Complete retests : cycles, stability, load response, consistency between units

Objective: that each Goodman heat pump regains stable, quiet operation and performance comparable to others.

Result: restored comfort, stable functioning, renewed confidence

After the procedure:

  • The cooling/heating has become uniform again across the zones.

  • disappearance of irregular cycles

  • A noticeable reduction in perceived vibrations

  • improved efficiency (the machine exerts less force, modulates better)

In this type of building, the benefit is immediate: fewer complaints, more comfort, and above all the certainty that the system is being properly maintained.

Our AirGreen recommendation for this type of Goodman (rooftop) installation

For Goodman rooftop wall-mounted heat pumps , we recommend:

  • regular preventative maintenance (before peak seasons)

  • an annual check of the fasteners/connections (wind + vibrations)

  • A "comparative" performance check between units: this is often where the problem is spotted before it becomes a breakdown

Why AirGreen for a Goodman repair in Montreal?

Because on a mini-split system, the difference between a "quick repair" and a professional intervention is the method:

  • diagnosis based on actual measurements

  • Clean intervention (roofing = strict adherence to regulations)

  • adherence to best practices (safety, stability, durability)

  • Transparency: we correct the cause, not just the symptom