Mechanical Ventilation with Heat Recovery systems, commonly known as MVHR, have become a central feature in modern energy-efficient homes. By continuously extracting stale air and supplying fresh, filtered air while recovering heat that would otherwise be lost, these systems help maintain indoor air quality and reduce heating costs. As building standards in places like United Kingdom and across Europe increasingly prioritize airtight construction, MVHR systems are no longer a luxury but an essential component of comfortable living. However, like any mechanical system, they require proper maintenance and occasional repairs to operate effectively.
Over time, an MVHR unit can develop issues that reduce performance or cause complete failure. Homeowners may first notice problems such as increased condensation on windows, lingering odors, or a drop in airflow from supply vents. In some cases, the unit may become unusually noisy, indicating worn bearings in the fans or loose internal components. Because MVHR systems run continuously, even minor faults can quickly escalate if not addressed. Early diagnosis and professional repair are crucial to prevent higher energy bills and compromised indoor air quality.
One of the most common repair needs involves faulty fans or motors. The fans are responsible for both extracting stale air and supplying fresh air, and they operate around the clock. Dust buildup, worn bearings, or electrical faults can cause the motor to overheat or fail entirely. When this happens, airflow becomes unbalanced, and the heat recovery process is disrupted. Replacing or refurbishing fan assemblies restores the system’s efficiency and ensures balanced ventilation throughout the property.
Heat exchanger problems are another frequent cause of MVHR repairs. The heat exchanger core transfers warmth from outgoing air to incoming fresh air without mixing the two streams. If the core becomes clogged with dirt or damaged due to freezing conditions, its efficiency drops significantly. In colder climates, improper installation or lack of insulation can lead to frost buildup inside the unit. Repair technicians may need to clean, repair, or replace the heat exchanger to restore optimal thermal performance.
Control systems and sensors also play a vital role in modern MVHR units. Many systems include humidity sensors, boost functions, and programmable controllers that regulate airflow based on occupancy and moisture levels. Electrical faults, damaged wiring, or outdated control boards can cause erratic performance. A malfunctioning controller might leave the unit running at high speed constantly or fail to activate boost mode when needed. Repairing or upgrading these electronic components ensures that the system responds accurately to environmental conditions.
Ductwork issues are sometimes overlooked during MVHR troubleshooting. Leaks, blockages, or poorly sealed joints can reduce airflow efficiency and place additional strain on the fans. Over time, flexible ducting may sag or accumulate debris, restricting MVHR repairs air movement. Professional repair services often include inspecting and resealing duct connections, clearing obstructions, and verifying that airflow rates meet the original design specifications. Proper duct maintenance not only resolves current issues but also extends the lifespan of the entire system.
Regular servicing can prevent many major repair needs. Routine tasks such as replacing filters, cleaning vents, and checking condensate drains help maintain smooth operation. When filters become clogged, the system must work harder, increasing wear on internal components. Annual professional inspections can identify early signs of wear before they turn into costly breakdowns. For homeowners, investing in preventative maintenance is far more economical than facing emergency repairs or complete unit replacement.
Ultimately, MVHR repairs are about preserving the balance between energy efficiency and indoor comfort. A well-functioning system quietly maintains fresh air circulation, controls humidity, and recovers valuable heat. When problems arise, timely diagnosis and skilled repair work restore performance and protect the long-term value of the property. As energy standards continue to tighten and demand for sustainable housing grows, keeping MVHR systems in peak condition will remain an essential part of responsible homeownership.