A Quick Service Call on a Flat Roof: Diagnosis and Repair of a Midea Outdoor Unit
At AirGreen , we are often called upon to work on Midea wall-mounted heat pump installations located on flat roofs of residential or commercial buildings. This type of configuration, although common in the Brossard region, requires specific expertise to ensure optimal operation in an environment exposed to the elements.
Background to the call
The client, the owner of a small commercial building, contacted us after noticing that his heat pump was no longer producing enough heat , even at moderate temperatures. The unit, a Midea 18,000 BTU model, was installed on a metal bracket above the roof, near the main drain. A quick visual inspection revealed a well-maintained outdoor unit, but with some rust at the screws and a slightly displaced protective cover over the cable routing.
Technical diagnosis
Our technician started with a series of standard tests:
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Check power supply : stable voltage, no tripped circuit breakers.
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Inspection of electrical connections : presence of slight slack in the power cable, causing intermittent poor contact.
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Analysis of refrigeration circuit pressures : pressures slightly lower than normal, sign of a micro-leak of refrigerant .
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Compressor and fan evaluation : operating correctly, but slowing down during extended cycles.
These elements confirmed a double problem: a minor gas leak combined with an unstable power supply .
On-site intervention
To correct these anomalies, we took the following steps:
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Tightening and securing the electrical connections inside the control box.
→ This type of repair, although simple, is essential to avoid power surges and repeated breakdowns. -
Leak detection using an electronic detector and application of a suitable sealant to the copper fitting.
→ We then performed a complete vacuum draw of the system to ensure the removal of moisture and impurities. -
Recharge with R-410A refrigerant according to Midea specifications.
→ The filling was precisely calibrated using an electronic scale. -
Performance test : After restarting, the heat pump reached full capacity in less than five minutes, with stable pressure and optimal heating efficiency .
Results and customer satisfaction
Once the repair was completed, the customer immediately noticed an improvement in hot air flow and a noticeable reduction in operating noise . We also recommended installing a snow cover and cleaning the outdoor coil annually to extend the unit's lifespan.
At AirGreen, we emphasize that even micro-leaks that are not visible to the naked eye can, in the long run, seriously affect the energy efficiency of a heat pump. This is why each intervention always includes a complete assessment of the system and a leak check .
Preventive maintenance tips
To avoid the recurrence of this type of breakdown, we recommend that owners:
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Visually check the cables and protective cover at least once per season.
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Have the coils and filters cleaned before each heating or cooling period.
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Schedule a complete annual maintenance by a certified technician, including checking the refrigerant charge .
An example of AirGreen reliability
This intervention in Brossard perfectly illustrates the combination of expertise and rigor that we apply to each service call. Thanks to our in-depth knowledge of Midea systems , we can ensure a durable and safe repair , while guaranteeing the thermal comfort of our customers on the South Shore of Montreal .