Mechanical Ventilation with Heat Recovery systems, often abbreviated as MVHR, have become a standard feature in modern airtight homes, providing both fresh air and energy efficiency. These systems are designed to extract stale, humid air from areas such as kitchens, bathrooms, and utility rooms, while supplying filtered, pre-warmed air to living spaces and bedrooms. The process involves a heat exchanger that transfers heat from outgoing air to incoming air without mixing the two streams, allowing homes to remain warm and well-ventilated with minimal energy loss. Despite their efficiency and durability, MVHR units are not immune to problems, and repairs are sometimes necessary to maintain optimal performance.
One of the most frequent issues in MVHR systems is reduced airflow. This can be caused by dirty or clogged filters, which restrict the passage of air and force the fans to work harder. Over time, this can put strain on fan motors and other mechanical components, reducing their lifespan. Many homeowners notice uneven ventilation in certain rooms or a lack of noticeable airflow from supply vents. In many cases, replacing or cleaning filters resolves MVHR repairs the problem, but if neglected, it can lead to further complications, including overheating of the fan motors or reduced heat recovery efficiency.
Fan motors themselves are another common area of concern. Since MVHR systems operate continuously, the motors endure constant usage, and bearings may wear out over time. Signs of motor failure include unusual noises such as rattling or humming, vibrations, or complete cessation of airflow in one or more sections of the home. Repairing a fan motor typically involves disassembling parts of the unit and ensuring that replacement components are compatible with the system. Improper repair can result in imbalanced airflow, further stressing the system and compromising efficiency.
Heat exchangers, while generally robust, can also become a source of performance issues. Dust accumulation, debris, or improper cleaning can reduce their ability to transfer heat effectively. In some cases, internal damage can occur, affecting both airflow and temperature regulation. When heat recovery efficiency drops, rooms may feel colder than usual, and the system may struggle to maintain balanced temperatures across the home. Professional servicing is often required to inspect, clean, or replace heat exchangers, as they are delicate and integral to the system’s performance.
Condensation management is another critical factor in MVHR repair. These systems naturally produce condensate as warm air loses heat while passing through the exchanger. Blocked or poorly installed drainage can lead to water accumulation inside the unit, potentially causing corrosion, electrical faults, or water leaks into surrounding structures. Regular inspection of condensate drains and proper maintenance prevent such problems and prolong the life of the system.
Control systems and sensors are also prone to faults, particularly in modern MVHR units with automated functions. Sensors monitor humidity levels, boost ventilation when necessary, and adjust fan speeds according to programmed settings. When sensors fail or control boards malfunction, the system may ventilate inadequately, leading to dampness and poor air quality, or over-ventilate, wasting energy. Diagnosing these issues requires specialized tools and knowledge of the specific manufacturer’s system.
Regular servicing is the key to minimizing repairs and maintaining efficiency. Annual inspections by qualified engineers ensure filters are replaced, ducts are clean and sealed, fans are functioning correctly, and electrical components are intact. Preventative maintenance protects both the investment in the system and the health of occupants by ensuring proper air quality and temperature balance.
Choosing the right repair specialist is also important. MVHR systems vary between manufacturers, and experienced technicians can diagnose issues more quickly and perform repairs correctly. Timely attention to problems, whether minor or major, helps preserve the energy-saving benefits of the system while ensuring consistent ventilation and indoor comfort. Neglecting repairs can lead to more extensive damage, higher energy bills, and reduced indoor air quality, making proactive maintenance essential for long-term performance.