When a wall-mounted heat pump starts to "run out of steam," it's not just a matter of comfort: it's often the first sign of a mechanical, electrical, or refrigeration problem that can quickly worsen. Recently, we were called out to Sainte-Rose (Laval) to repair an Elios wall-mounted heat pump (compact outdoor unit, residential installation on a raised support, refrigerant lines protected by a casing).
In this article, we show you how we diagnosed the fault , what repairs were carried out and how we validated the result, all in a clear and concrete approach – exactly as we do in the field at AirGreen.
The context: an Elios wall-mounted heater that was no longer heating as well as before
The client contacted us because the system:
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it heated less efficiently , especially during colder periods;
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seemed to take longer to reach the desired temperature;
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sometimes gave the impression of "starting/stopping" irregularly.
On a wall-mounted heat pump, these kinds of symptoms can stem from several causes (sensors, communication issues, restrictions, ventilation problems, fouling… or lack of refrigerant ). Our role: not to guess , but to measure and confirm.
What the photo reveals: important installation details
Even before touching the system, certain visible elements indicate a typical and logical installation context :
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Elios outdoor unit installed on a raised metal support (good practice to reduce exposure to snow, leaves, and limit humidity at the bottom of the unit).
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Base placed on slabs , with stabilizing block under the support: we always check the level and rigidity to avoid vibrations and stresses on the joints.
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Refrigerant lines are insulated and protected by a vertical chute (covering), which limits UV and mechanical damage.
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Visible electrical connection on the unit side: we systematically inspect the tightness, sheathing, protection and general condition.
These details matter: an elevated and well-dressed installation often protects the equipment… but the fittings (flanges/tightenings) remain areas where a micro-leak can appear over time (vibrations, hot/cold cycles, expansion).
AirGreen Diagnosis: Step-by-step method (no assumptions)
On site, we followed our diagnostic protocol for wall-mounted heat pumps:
1) Functionality check and symptom reading
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Test in heating then in air conditioning (depending on conditions).
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Observation of the behavior of the outdoor fan, the inverter compressor, and the cycles.
2) Electrical controls and communication
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Inspection of connections (power + communication).
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Basic steps to confirm that the unit is correctly receiving its signals and power.
3) Refrigeration checks (pressures, temperatures, consistency)
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Readings of parameters to validate if the system is within its normal range.
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Search for inconsistencies typical of an insufficient load : low efficiency, abnormal cycle time, less efficient heat exchange.
4) Targeted leak detection
In this case, the signs pointed to a problem with the refrigeration circuit. We therefore carried out a thorough inspection of the connections near the outdoor unit (the area most exposed to micro-movements).
Result: micro-leak at a fitting (flare type), small enough not to "break down completely", but large enough to cause the performance to drop over time.
The repair: fixing the connection, leak testing, and putting it back into service.
Once the origin was confirmed, we proceeded with a complete and clean repair:
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Correction of the faulty connection
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Disassembly, inspection of the scope, correction/adjustment according to the observed condition.
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Reinstallation with a methodical approach (alignment, controlled tightening, prevention of stresses).
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Pressure leak test (nitrogen)
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Pressurization and monitoring to confirm that there is no further loss.
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Vacuuming
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Rigorous vacuuming to eliminate moisture and contaminants (essential for reliability and performance).
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Recharging / adjustment
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The system is brought back to a suitable load, then validated by measurements in operation.
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Final checks
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Complete test in heating/cooling mode.
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Airflow control, operational stability, and normal behavior of the outdoor unit.
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Result: restored comfort, normalized cycles, renewed confidence
After the intervention, the Elios heat pump:
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has returned to normal performance (more pronounced heating, faster temperature rise);
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operates stably , without irregular behavior;
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allows the customer to feel confident, with a documented and verified repair.
This is exactly the kind of situation where a "we'll see later" approach is costly: an untreated micro-leak can lead to progressive degradation, over-stressing of the compressor, and possibly a more serious breakdown.
Why this type of problem occurs (and how to avoid it)
Even with a good installation, certain factors can cause a micro-leak over time:
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thermal cycles (expansion/contraction);
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vibrations if the support moves slightly or if the device is no longer perfectly stable;
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constraints on refrigeration lines (tension, torsion, alignment).
Good practice : if you notice a drop in performance, abnormal cycles, or inconsistent comfort, it's best to get a diagnosis early. A simple repair today can prevent a major replacement tomorrow.
AirGreen in Laval and throughout Greater Montreal
At AirGreen, we service wall-mounted heat pumps like this Elios every week, whether it's for:
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performance diagnosis,
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leak repair,
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maintenance and cleaning,
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electrical/electronic repair
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Complete recommissioning with testing.
Our goal remains the same: to repair properly, measure, validate, and leave you with a reliable system .