A VRC-95 air exchanger installed above the water heater: a service call where every detail mattered
In a residence in Villeray–Saint-Michel–Parc-Extension, our AirGreen team responded to a service call for an Épurair VRC-95 air exchanger installed in a very compact mechanical space, directly above a Giant water heater. The client had noticed several uncomfortable signs in the residence: heavier indoor air, persistent humidity, occasional condensation on some cold surfaces, and the impression that the device was no longer ventilating as before.
This type of intervention requires precise analysis because a residential air exchanger is not just a box that pushes air. It contributes to the overall balance of the house: extracting stale air, bringing in fresh air, reducing humidity, improving indoor air quality, and maintaining comfort stability. When it malfunctions, symptoms can appear throughout the home, even if the real cause is in a small mechanical room that is hard to access.
In this case, the visible device was a Épurair VRC-95, a VRC-type air exchanger, installed in a wall niche above the hot water tank. The location was convenient for saving space but complicated maintenance: limited clearance, tight access to the sides of the device, exposed wiring, vertical drain descending behind the water heater, and ducts partially hidden in the ceiling.
Symptoms reported by the client
The client contacted us because the air in the residence seemed less refreshed than before. The sensation was particularly noticeable after showers, during cooking, and in colder periods when windows remain closed. This kind of situation is common in Montreal, especially in renovated or better-insulated homes, where the building’s airtightness limits natural air infiltration.
The observed symptoms were consistent with an air exchanger that is working but with reduced efficiency:
- indoor humidity more difficult to control;
- odors that linger longer in certain rooms;
- less noticeable ventilation at the grilles;
- slightly different noise at startup;
- dust buildup around the device;
- suspected partially blocked or poorly drained condensate drain;
- intermittent operation depending on cycles.
An air exchanger can become less efficient without completely breaking down. This often makes diagnosis more difficult: the device still makes noise, so the client thinks it’s working, but airflow, the recovery core, filters, or drainage may be compromised.
Initial inspection of the Épurair VRC-95 installation
Upon arrival, we first inspected the mechanical environment. The device was installed above a Giant water heater, with ducts and cables visible on the right side. Access to the front panel was possible, but the workspace was limited. In this kind of setup, we must proceed carefully to avoid damaging plumbing connections, condensate lines, electrical cables, or ventilation ducts.
We checked:
- the overall condition of the air exchanger housing;
- the electrical supply;
- access to the service panel;
- the condition of the filters;
- the cleanliness of the recovery core;
- the operation of ventilation motors;
- mechanical noise at startup;
- the presence of vibration;
- the condition of the condensate drain;
- the visible condition of connected ducts;
- the consistency of airflow at accessible outlets.
The device was not completely off. It was receiving power and responding to commands. However, its actual performance was reduced. The filters showed dust buildup, the core needed cleaning, and the drain had to be checked to ensure condensed moisture was properly evacuated.
Why a poorly maintained air exchanger quickly affects comfort
A Épurair VRC-95 air exchanger is used to renew indoor air while limiting energy loss thanks to its recovery core. In winter, the outgoing air transfers part of its heat to the incoming fresh air. In summer or intermediate seasons, the device also helps maintain better air circulation, depending on settings and building needs.
When filters clog or the core gets dirty, several problems arise:
Reduced airflow
The device works harder to move the same volume of air. The renewal becomes insufficient, even if the motor is running.
Higher humidity
If humid air is not properly extracted, the house can retain too much moisture. This promotes fogging, odors, and sometimes the appearance of mold in cold or poorly ventilated areas.
Noise or vibration
A motor that strains, a dusty fan wheel, or a poorly closed casing can produce more noticeable noise.
Unnecessary consumption
A dirty air exchanger can run for a long time without delivering the expected result. The system then consumes electricity without ensuring effective ventilation.
Technical diagnosis: filters, core, motors, and drainage
Our diagnosis began with the safe power shutdown of the device. We then opened the front panel to access the internal components. On a residential air exchanger, this step must be done correctly, as a poorly repositioned panel after maintenance can cause air leaks or vibrations.
Clogged filters
The filters were loaded with dust. It was not an extreme blockage, but enough to limit airflow. In an urban neighborhood like Villeray–Saint-Michel–Parc-Extension, outdoor air often carries fine particles, pollen, street dust, and contaminants that eventually accumulate in the system.
Heat recovery core to clean
The HRV core showed an accumulation that reduced the efficiency of air transfer. A dirty core prevents the device from breathing properly. We carefully removed it, inspected it, cleaned it according to best practices, then allowed it to dry properly before reinstalling.
Fans and motors
We tested the ventilation motors to confirm their operation. The startup was present, but the airflow was weaker than expected before cleaning. After cleaning the filters and core, the flow improved. No major motor replacement was necessary during this intervention.
Condensate drain
The vertical drain visible under the device was checked. On an air exchanger, a partially blocked drain can cause water accumulation inside the casing, odors, moisture marks, or even leaks near the water heater. We cleaned the accessible line, confirmed the drainage slope, and verified that water could flow properly.
Intervention carried out by AirGreen
The intervention was structured to restore the air exchanger without unnecessary replacement. We carried out a complete maintenance and repair focused on the real causes of the problem.
The main steps were as follows:
- safe power shutdown of the device;
- opening of the front panel;
- removal and cleaning of filters;
- inspection of the heat recovery core;
- core cleaning;
- checking the fans;
- checking for noise and vibrations;
- cleaning of the condensate drain;
- reinstallation of components;
- complete operational test;
- checking airflow at accessible grilles;
- maintenance advice to the customer.
This approach helps avoid a common mistake: replacing a device when the problem simply comes from lack of maintenance, a blocked drain, or reduced airflow due to dust accumulation.
The result: better renewed indoor air and a more stable device
After the intervention, the Épurair VRC-95 air exchanger returned to more regular operation. The airflow was more noticeable, mechanical noise was more stable, and the device responded better to demand. The customer was reassured because the equipment did not need to be replaced in the short term.
The most important gain is not measured only by noise or immediate airflow. It is felt in indoor air quality: less stagnant air, better moisture evacuation, less persistent odors, and more consistent comfort in the home.
Practical lessons from this air exchanger repair in Montreal
A service call for an air exchanger is often triggered when the customer notices discomfort, but the cause lies in technical details invisible on a daily basis. In this project in Villeray–Saint-Michel–Parc-Extension, the device was functional but no longer working under optimal conditions.
A compact location requires more regular maintenance
Installation above a water heater is common in homes where mechanical space is limited. However, this type of location requires special attention. Ambient heat, limited access, tight ducts, and proximity to plumbing can make maintenance more difficult.
A device that is difficult to access is often less maintained, not out of negligence, but because the filters and core are less visible. Yet, it is precisely in these installations that maintenance becomes most important.
Mistakes to avoid with a residential air exchanger
Several problems can be avoided with good habits:
- do not wait for the device to stop working completely;
- do not leave the filters in place for several years;
- do not block the air grilles in the rooms;
- do not turn off the device in winter under the pretext of saving energy;
- do not ignore damp odors;
- do not neglect the condensate drain;
- do not replace the device before confirming the diagnosis.
A well-maintained air exchanger can greatly contribute to home comfort, but only if internal components stay clean and ducts allow good airflow.
When should you have an air exchanger checked?
It is recommended to request HVAC service when any of the following signs appear:
- frequent condensation on windows;
- lingering odors;
- heavy or humid indoor air;
- unusual noise in the unit;
- low airflow at the vents;
- water or moisture near the unit;
- very dirty filters;
- unit running without noticeable effect;
- poorly closed panel or casing vibration;
- increased discomfort in winter when windows remain closed.
In Montreal, Laval, Longueuil, on the North Shore and the South Shore, we regularly encounter this type of situation in condos, multiplexes, renovated houses, and homes with compact mechanical rooms.
The importance of a complete diagnosis rather than a quick fix
At AirGreen, we approach every HVAC repair with a clear method. For an air exchanger, we don’t just say the unit works because it makes noise. We check airflow, filters, the core, motors, drain, visible ducts, and installation conditions.
In this case, the solution came from precise work: cleaning, inspection, drainage correction, and operation validation. No costly replacement was required. The client received a solution tailored to their unit and building.
AirGreen for air exchanger repair and maintenance
This service on a Épurair VRC-95 air exchanger in Villeray–Saint-Michel–Parc-Extension highlights the importance of professional service when a residential ventilation system loses efficiency. A VRC directly affects the building’s health, occupant comfort, and humidity management.
Our team handles air exchanger repair, preventive maintenance, ventilation diagnostics, component cleaning, drain inspection, and indoor air quality optimization throughout the greater Montreal area. Whether the unit is installed in a basement, mechanical room, closet, condo, or multiplex, we tailor our service to the site’s conditions.