How do they compare to other systems?

Just like any system MVHR needs regular maintenance, in much in the same way you’d get your central heating checked every autumn. Here’s why ongoing regular checks are important, complete with some practical guidance.

Just because you can’t see it…

Domestic ventilation systems tend to be hidden away, out of sight. But that doesn’t mean they’re out of mind. Because it’s not obviously visible it’s tempting to ignore your MVHR system and let it do its own thing. On the other hand leaving it too late means repair and maintenance can cost a lot more than it needs to.

There’s another great reason for having your system checked annually. Leaving the system alone for too long means it can get less and less efficient over time, a frustrating state of affairs which condemns the unit to a lifetime of poor performance, inefficiency and wasted energy.

Your first step, when you either get MVHR fitted or move in somewhere which already has it, is to diary regular maintenance.


Your second step? RTM… AKA Read The Manual to find full instructions and contact details for maintenance and support. Did you know, for example, that many experts recommend the filters are checked and cleaned on all new builds just before the finished building is handed over to the new owners? It makes sense because building work is a dusty business and your new unit might need a fresh filter before you even move in. And did you know it’s also wise to leave the unit set at ‘boost’ for a few days or weeks to get rid of the extra moisture you often find in the fabric of a brand new building, another time when a new filter might be what you need?

It also helps if you have a basic understanding of how MVHR works. It’s simple enough to understand and just a small amount of knowledge will help you spot any problems quickly. While mechanical ventilation heat recovery systems are often tucked away in inaccessible roof spaces or airing cupboards, kitchen units, larders and utility rooms, knowing where they are means you can have a quick visual check now and again to make sure everything looks ‘normal’.

How are householders and landlords supposed to tell if something isn’t working properly? You’ll never really know unless you get the system maintained and serviced regularly, in the same way as you would ordinary gas or electric central heating… and keep your eye on it.

Why is MVHR servicing and maintenance so important?

A blocked or clogged filter can make life very difficult for your system’s fan as it struggles to force air through the muck. This can make the entire system unacceptably noisy as well as impeding the airflow so the air in the building isn’t very good quality. Which can in turn damage your health. It can lose you money too, as the systems cost more to run when their efficiency is compromised.

Stricter regulations have been in place since 2010, with Approved Document Part F (ADF) 2010 ensuring a change for the better and driven better quality installations. And Part L offers enhanced ratings for systems installed by a member of a recognised Competent Persons Scheme. If your MVHR maintenance person hasn’t taken a proper accredited maintenance course – usually run by system manufacturers – find someone who has.

Perhaps one day we’ll live in a world where maintaining our MVHR units is second nature, just like changing our hoover bags. It’s impossible to over-estimate the importance of maintenance… but too many people still do. If that’s you, grab your diary, choose a date and book a professional to carry out regular servicing and maintenance. As the Energy Saving Trust says:

“Regular maintenance should be carried out to ensure the system is still in balance, that filters and grilles are clean, and that the system is functioning correctly. Fans and heat exchangers will also need to be cleaned regularly.”