Signs Your MVHR System Needs Repair and How to Fix It

MVHR systems are designed to run efficiently with minimal intervention, but like any mechanical system, they can develop faults over time. Identifying early warning signs can prevent expensive breakdowns, poor indoor air quality, and increased energy costs.

Many UK homeowners experience weaker airflow, unusual noises, or rising electricity bills without realising these could indicate MVHR issues. Knowing when to seek professional repairs or perform simple fixes can extend your system’s lifespan and ensure consistent performance.

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The Growing Need for MVHR Repairs in the UK

With UK homes becoming more airtight, MVHR systems play a critical role in preventing condensation, mould, and stale air. A malfunctioning unit can lead to:

• Higher energy consumption due to inefficient heat recovery
• Increased humidity and potential damp problems
• Poor ventilation, leading to a buildup of pollutants

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Case Study: A Homeowner’s MVHR Repair Experience

A homeowner in Birmingham noticed whistling noises and weak airflow from their MVHR system. After an inspection, an engineer found:

• A clogged heat exchanger, reducing airflow by 40%
• Loose ducting, causing noise and heat loss

Once the heat exchanger was cleaned and the ducting re-sealed, airflow returned to normal, and heating costs dropped by 20%.

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Common MVHR Issues and How to Fix Them

1. Low or No Airflow
   • Possible Causes: Blocked filters, faulty fans, or duct obstructions
   • Solution: Clean or replace filters; check for airflow blockages in ducts
2. Unusual Noises (Humming, Whistling, or Rattling)
   • Possible Causes: Loose duct connections, worn-out fan motors, or debris in the system
   • Solution: Secure ducting, inspect for obstructions, and check motor bearings
3. High Energy Bills
   • Possible Causes: Inefficient heat exchanger, blocked vents, or incorrect system settings
   • Solution: Ensure heat recovery components are clean and correctly calibrated
4. Condensation or Mould Growth
   • Possible Causes: Poor ventilation balance or duct leaks
   • Solution: Adjust airflow settings and check for improperly sealed ducts
5. Unpleasant Odours or Stale Air
   • Possible Causes: Clogged filters, bacterial growth, or contaminated ducting
   • Solution: Replace filters, clean vents, and disinfect ducting periodically

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