How Often Should a PIV Unit Be Serviced?

If you have a Positive Input Ventilation (PIV) unit installed in your home, you've made a smart investment in air quality and damp prevention. But like any mechanical appliance — your boiler, your car, your extractor fan — a PIV unit needs regular attention to keep working as it should.

The question we get asked more than any other is: how often does a PIV unit actually need servicing? Here's the honest answer from engineers who work on these systems every week.

What the Manufacturers Say

Most of the leading PIV manufacturers — including Envirovent, Nuaire, Ventaxia and Airmaster — recommend that their units are serviced at least once every 12 months. Some have historically recommended a service every five years, though in practice we find that units benefit significantly from more frequent attention than that.

For warranty purposes, it's worth checking your specific product documentation. Several manufacturers require evidence of regular servicing to honour a warranty claim, so keeping a record of each visit matters.

What Actually Happens During a Service?

A proper PIV service isn't just a quick look and a wipe down. Here's what our engineers check on every visit:

• Filter inspection and replacement — the filter is the heart of the unit, trapping dust, pollen and particulates. A clogged filter doesn't just reduce air quality; it puts strain on the fan motor.
• Fan motor check — we listen for unusual noise, check bearing condition and verify the motor is running at the correct speed.
• Airflow measurement — we measure the air being delivered through the ceiling diffuser and re-commission to manufacturer specification if it's drifted.
• Electrical safety check — supply voltage, connections and any control systems are inspected.
• Loft environment inspection — we check that the unit is properly positioned, that there's no condensation on the casing, and that the loft itself isn't causing problems.
• Summer bypass and sensors — where fitted, temperature probes and bypass dampers are tested.

At the end of every visit, we issue a written service certificate documenting everything we've done and any recommendations.

What Happens If You Skip a Service?

This is where it gets important. A PIV unit that hasn't been serviced will carry on running — and many homeowners assume that because it's still spinning, everything is fine. Unfortunately that's not always the case.

Over time, without servicing:

• The filter becomes blocked, reducing airflow and pushing the motor harder to compensate
• Reduced airflow means less fresh air entering the home — condensation and damp can begin to return
• Strain on the motor shortens its lifespan, potentially leading to early unit failure
• Any small issues — a loose connection, a worn bearing — go undetected until they become expensive problems

Does the Brand Affect How Often It Needs Servicing?

In terms of service interval, most brands align on annual servicing. Where brand matters more is the quality and specification of the filter. Units from manufacturers like Envirovent and Ventaxia use higher-grade filter media that is more effective — but also more expensive to replace when the time comes.

This is why our service prices vary slightly by brand. It reflects the actual cost of the components needed to do the job properly, not an arbitrary premium.

How Do I Know If My Unit Needs a Service Now?

Even if it hasn't been 12 months, there are signs that your PIV unit may need attention sooner:

• Condensation or mould returning to rooms that previously were clear
• Unusual noise from the loft — grinding, rattling or a change in hum
• Noticeably less airflow from the ceiling diffuser
• A musty smell from the unit
• The unit running constantly at high speed without apparent reason

Any of these warrants a service call, regardless of when the last visit was.

We Cover North England & Mainland Scotland

ServiceMyPIV covers the whole of North England — from Hull across to Lancaster and all the way north — plus all of mainland Scotland including the Highlands. If you're in Yorkshire, Lancashire, Cumbria, Northumberland, County Durham, Tyne and Wear, the Scottish Borders, Edinburgh, Glasgow, Aberdeen or anywhere in between, we can help.

Our engineers are brand-trained across all major PIV manufacturers. Whether you have a Nuaire Drimaster, an Envirovent unit, a Ventaxia Lo-Carbon PIV or an Airmaster system, we service them all.