Ventilation service

A professional ventilation service ensures your system operates quietly and efficiently, protecting your property’s structural integrity and your family's health. Regular maintenance also extends the lifespan of expensive components, preventing the need for costly emergency replacements.

What Does the Work Involve?

• System Inspection: A thorough check of mechanical fans, passive vents, grilles, and all visible ductwork for damage or blockages.
• Airflow Testing: Using anemometers to measure the actual volume of air being moved, ensuring it meets Building Regulations (Part F) requirements.
• Deep Cleaning: Removing dust, grease, and debris from fan housings, impellers, and internal grilles to restore performance and reduce noise.
• Filter Replacement: Swapping out saturated filters in MVHR or MEV units to maintain air hygiene and protect the heat exchanger.
• Electrical Safety: Checking wiring connections, isolation switches, and fan motors to ensure the system is electrically sound.
• Performance Report: Providing a written summary of airflow readings, work completed, and any recommendations for repairs or upgrades.

Typical Costs

Prices vary based on the complexity of the system and the size of your property. Routine servicing for a standard extract fan is significantly cheaper than a full commission or service of a whole-house MVHR system.

Note: Prices generally include VAT at 20%. Costs may increase if the engineer discovers significant ducting issues or if the system requires a complete re-balancing of airflows across multiple rooms.

How Long Does It Take?

• Single Room Extract Fan: 45 minutes to 1.5 hours for a standard clean and test.
• Whole-House MVHR Service: 2 to 4 hours, depending on the number of wet rooms and accessibility of the main unit.
• Fan Replacement: 1 to 2 hours, assuming existing ducting and wiring are in good condition.
• Ductwork Cleaning: 4 to 8 hours for a full residential system using specialist vacuum equipment.

DIY or Professional?

Homeowners can easily perform basic maintenance, such as vacuuming dust from external grilles or wiping down plastic covers. However, most ventilation work should be left to a professional, particularly when dealing with electrical components or system balancing.

Replacing a fan or working on fixed wiring falls under Part P of the UK Building Regulations, which often requires a competent person or notification to local building control.

Professional engineers use calibrated equipment to ensure your home meets the minimum ventilation rates required by law. Incorrect DIY adjustments can lead to "short-circuiting" airflows, resulting in persistent condensation and mould growth in neglected rooms.

Choosing the Right Tradesperson

• Check Qualifications: Look for engineers with BPEC (Ventilation) certification or those registered with NICEIC or NAPIT.
• System Expertise: Ensure they are familiar with your specific brand (e.g., Vent-Axia, Nuaire, Zehnder) as parts and software vary.
• Red Flags: Avoid "handymen" who do not carry airflow meters or those who suggest "just turning the fan off" to save energy.
• Ask: "Will you provide a commissioning sheet with the measured airflow rates (l/s) after the service?"
• Ask: "Do you carry spare filters and sensors, or will these need to be ordered separately?"
• Ask: "Are you insured for work at height if my external vents are on the second floor?"

UK Regulations

• Approved Document F: This is the primary regulation governing ventilation rates in UK dwellings. It dictates the minimum litres per second (l/s) of air that must be extracted from "wet rooms" like kitchens and bathrooms.
• Approved Document P: Covers electrical safety in dwellings. Most fan installations in bathrooms (Zones 1 and 2) must comply with strict safety standards.
• Domestic Ventilation Compliance Guide: This document outlines how systems should be tested and commissioned. You should receive a signed copy of the commissioning checklist for new installations.

Common Problems

• Excessive Noise: Often caused by a build-up of dirt on the impeller blades, which unbalances the motor, or loose ductwork vibrating against ceiling joists.
• Backdrafts: If a backdraft shutter is broken or missing, cold air can blow into the house when the fan is off, significantly reducing energy efficiency.
• Persistent Condensation: Usually indicates the fan is underpowered for the room size or the ducting is too long/restricted for the fan's pressure capacity.
• Water Leaking from Fan: Often caused by condensation forming inside uninsulated ducting in cold loft spaces and running back down to the unit.
• Blocked Filters: In MVHR systems, blocked filters force the motors to work harder, increasing electricity bills and reducing air quality.

Frequently Asked Questions

How often should I service my ventilation system?

Standard extract fans should be cleaned every 12 months. MVHR systems require a professional service every 2 years, though you should check and clean the filters yourself every 3 to 6 months.

Why is my bathroom fan still running after I turn the light off?

Most modern fans have an "overrun timer" designed to clear moisture after you leave the room. This can usually be adjusted between 2 and 20 minutes; if it runs indefinitely, the sensor or timer module may be faulty.

Do I need to replace my ducting during a service?

Not usually. Unless the ducting is crushed, disconnected, or heavily contaminated with mould, a simple clean is sufficient. However, flexible "concertina" ducting is prone to damage and may need replacing with rigid pipes for better airflow.

Can a ventilation service help with my allergies?

Yes, especially if you have an MVHR system. High-grade filters (F7 or higher) can remove pollen and fine particulate matter from the incoming air, significantly improving symptoms for hay fever and asthma sufferers.

What is the difference between MEV and MVHR?

MEV (Mechanical Extract Ventilation) is a central fan that continuously pulls air from wet rooms. MVHR (Mechanical Ventilation with Heat Recovery) does the same but also brings fresh air in, using a heat exchanger to warm the incoming air with the heat from the extracted air.