Mechanical Ventilation with Heat Recovery systems, commonly known as MVHR, have become an essential feature in modern energy efficient homes. As building standards have improved and airtight construction has become the norm, systems such as Mechanical Ventilation with Heat Recovery have been widely installed to provide continuous fresh air while retaining as much heat as possible. By extracting stale air from kitchens and bathrooms and supplying filtered fresh air into living spaces, MVHR units help maintain indoor air quality, reduce condensation, and lower heating bills. However, like any mechanical system, they can develop MVHR repairs faults over time and require professional repair and maintenance to keep operating effectively.
One of the most common reasons homeowners seek MVHR repairs is reduced airflow. When a system is not delivering adequate ventilation, rooms may feel stuffy and condensation may begin to form on windows. Often the cause is relatively simple, such as clogged filters that have not been replaced according to the manufacturer’s schedule. Filters typically need changing every six to twelve months depending on usage and environmental conditions. If they become blocked with dust and debris, airflow is restricted and the system has to work harder, potentially leading to overheating or premature component wear. In more serious cases, reduced airflow may be linked to failing fans, damaged ductwork, or control board faults that require professional diagnosis.
Noise is another common indicator that MVHR repairs may be needed. While these systems are designed to operate quietly in the background, unusual humming, rattling, or vibration can signal problems. Worn bearings in the supply or extract fans can create grinding sounds, while loose duct connections may cause rattling when air passes through. In some situations, debris inside the unit or imbalanced fan blades can increase noise levels. Addressing these issues promptly is important, as prolonged operation with worn components can lead to more extensive damage and higher repair costs.
Heat recovery efficiency is also a key factor in the performance of an MVHR system. The central heat exchanger is designed to transfer warmth from outgoing stale air to incoming fresh air without mixing the two air streams. If the heat exchanger becomes dirty or damaged, its efficiency can drop significantly. This may result in colder supply air and increased heating demand within the property. Professional servicing often includes cleaning the heat exchanger and checking seals to ensure optimal thermal performance. In some cases, replacement of the heat exchanger core may be necessary if it has cracked or deteriorated.
Electrical and control issues can further complicate MVHR operation. Modern systems frequently include digital controllers, humidity sensors, and boost functions that automatically increase ventilation when moisture levels rise. Faulty sensors may cause the system to run continuously at high speed or fail to respond when needed. Wiring faults, blown fuses, or damaged circuit boards can also interrupt operation entirely. Because these components involve electrical work, repairs should always be carried out by qualified technicians to ensure safety and compliance with regulations.
Preventative maintenance plays a crucial role in reducing the need for major MVHR repairs. Regular inspections can identify minor issues before they escalate. Checking duct connections for air leaks, ensuring condensate drains are clear, and confirming that airflow rates are correctly balanced all contribute to long term reliability. Proper commissioning after installation is equally important, as poorly balanced systems are more prone to performance issues and occupant complaints.
Investing in timely MVHR repairs not only restores comfort but also protects the energy efficiency benefits that these systems are designed to deliver. A well maintained unit supports healthy indoor air quality, minimizes heat loss, and extends the lifespan of the equipment. For homeowners in modern airtight properties, ensuring that their ventilation system remains in optimal condition is essential to preserving both comfort and long term value.
