Mechanical Ventilation with Heat Recovery systems, commonly known as MVHR systems, have become an essential feature in modern energy-efficient homes. Designed to provide a continuous supply of fresh air while retaining heat that would otherwise be lost, these systems support both indoor air quality and energy savings. As airtight construction standards become more common across the UK and Europe, MVHR units are no longer considered luxury additions but core building components. However, like any mechanical system, they require maintenance MVHR repairs and occasional repairs to function effectively over the long term.
MVHR systems operate by extracting stale air from wet rooms such as kitchens and bathrooms while supplying filtered fresh air into living spaces and bedrooms. The outgoing air passes through a heat exchanger, transferring its warmth to the incoming air without mixing the two air streams. Over time, wear and tear can affect components such as fans, heat exchangers, control boards, sensors, and ducting connections. When faults develop, the performance of the entire ventilation system can decline, often without homeowners immediately noticing.
One of the most common reasons for MVHR repair is reduced airflow. This may present as lingering condensation on windows, persistent cooking smells, or uneven temperatures throughout the property. Blocked filters are frequently the culprit, but if filters have been regularly replaced, the issue may lie with failing fan motors or obstructions within the ductwork. Professional diagnosis is important because airflow imbalance can strain the system and increase energy consumption.
Unusual noises are another indicator that repairs may be necessary. MVHR units are designed to run quietly in the background, so rattling, humming, or grinding sounds usually signal a mechanical issue. Bearings within the fans may be wearing out, mounting brackets may have loosened, or debris may have entered the unit. Addressing these problems early can prevent more extensive damage and avoid complete system failure.
Electrical faults can also affect MVHR systems. Modern units rely on control panels, humidity sensors, frost protection systems, and circuit boards to regulate performance. If the system fails to power on, runs intermittently, or displays error codes, a qualified technician should inspect the electrical components. Attempting DIY repairs on electronic elements can void warranties and pose safety risks. In many cases, faulty sensors or damaged wiring can be replaced without requiring a full system upgrade.
Heat exchanger issues represent a more technical repair category. The heat exchanger core is central to the system’s energy efficiency. If it becomes cracked, blocked, or excessively dirty, heat recovery performance drops significantly. In colder climates, frost protection failures may cause freezing inside the unit, which can damage internal components. Regular servicing reduces the likelihood of such problems, but if they occur, prompt intervention protects both comfort and running costs.
Ducting problems are sometimes overlooked during MVHR repair discussions. Poor installation, disconnected joints, or crushed duct sections can restrict airflow and reduce system effectiveness. Leaks within duct runs may allow conditioned air to escape into loft spaces rather than reaching intended rooms. Repairing or resealing ductwork can restore balance and improve indoor air quality without replacing the main unit.
Preventative maintenance plays a crucial role in reducing repair frequency. Filters should typically be replaced every six to twelve months, depending on environmental conditions. Annual servicing by a qualified ventilation engineer ensures that airflow rates are checked, components are cleaned, and electrical systems are tested. This proactive approach extends the lifespan of the unit and maintains compliance with building performance standards.
When considering MVHR repairs, it is important to work with specialists familiar with specific system brands and models. Parts availability, compatibility, and warranty considerations vary between manufacturers. In some cases, upgrading individual components such as control panels or fans can modernise older systems without the expense of a full replacement. However, if a unit is approaching the end of its design life, a cost comparison between repair and replacement may be advisable.
Ultimately, MVHR repairs are about preserving the balance between energy efficiency, air quality, and occupant comfort. A properly functioning system quietly supports a healthier indoor environment while reducing heating demand. Addressing faults promptly, investing in regular servicing, and using qualified professionals ensures that the system continues to perform as intended for many years.