How Often Does Your Commercial Kitchen Extraction System Need Cleaning?

Every time the fryers, grills or ovens fire up, grease-laden air gets pulled straight into the extraction system. Unlike a kitchen at home, where cooking happens for an hour or two a day, commercial kitchens run hard for hours on end, so grease builds up far quicker than most operators expect. TR19® Grease provides recognised guidance on how commercial kitchen extract systems should be inspected and cleaned, so you’re working from proper guidance rather than guesswork.

This post walks you through how often you need to book your extraction system for a proper clean, and why sticking to that schedule matters more than most people realise.

The hidden dangers of skipping regular cleaning

Neglecting your extraction system puts your kitchen at serious risk of fire, poor air quality and rising running costs, so regular cleaning isn’t a nice-to-have; it’s essential. Kent Fire and Rescue Service has reported that around 70% of commercial kitchen fires involve faulty or grease-contaminated extraction systems. Fat and grease are highly flammable. Once they build up inside your ductwork, it takes surprisingly little to set things off.

There’s more at stake than fire safety, too. A clogged system struggles to shift smoke and cooking fumes out of your kitchen, which makes for a hotter and far less pleasant place to work a shift. Your extractor fan has to work harder as well, which pushes up your energy bills while wearing the motor out well before its time. Keep the system clean for better air quality, lower running costs and equipment that actually lasts. Think of it as a bit of TLC before the fan starts protesting.

TR19 cleaning intervals: how often should you clean?

TR19 cleaning intervals depend on how many hours your kitchen runs each day, ranging from every three months for heavy use down to every 12 months for light use.

BESA, the Building Engineering Services Association, sets out these intervals as part of the TR19 standard. They form the cleaning schedule widely expected by insurers and commonly used as good practice by Environmental Health Officers (EHOs).

Here’s how the standard breaks down.

• Heavy use, 12 to 16 hours a day: clean every three months.
• Moderate use, 6 to 12 hours a day: clean every six months.
• Light use, 2 to 6 hours a day: clean every 12 months.

Most sit-down restaurants and busy takeaways fall into the heavy or moderate categories. A hotel kitchen running breakfast through to late dinner service, for example, is likely looking at extraction system cleaning twice a year at minimum, possibly more depending on what’s often cooked. Got a wok-heavy menu? That’s a recipe for a busier cleaning schedule, too.

These figures are baseline intervals, though, not a ceiling. The type of cooking matters just as much as the hours on the clock. Deep-frying and anything involving solid fuel like wood or charcoal produces far more grease than a kitchen running mostly grills and ovens, and that can push your cleaning schedule up to monthly. A professional contractor will usually assess your kitchen at the survey stage to confirm which category you actually fall into, rather than leaving you to work it out yourself. Get it wrong, and you’re either paying for cleans you don’t need, or running a system well past the point it’s safe to do so.

What parts of the extraction system need cleaning?

Extraction system cleaning covers everything from a daily wipe-down through to a full specialist deep clean, and the two shouldn’t be confused. In-house staff can manage the daily basics. The hidden parts of the system need a professional.

What your team can handle

Canopy surfaces need a daily wipe-down as part of normal kitchen cleaning. Metal grease filters should be cleaned regularly, often daily or weekly, depending on use. That much is well within reach for most kitchen staff.

What needs a professional

Everything else is a different story. The internal ductwork, the canopy plenum, and the extractor fan and motor sit largely out of sight, which is exactly why they get neglected. Reaching them safely takes specialist equipment and training. A proper deep clean strips grease deposits out of every section of ductwork, not just the bits you can see from standing on a chair.

Think of your filters as the first line of defence and the ductwork as the last. Stay on top of both, and your kitchen canopy cleaning frequency stops being a guessing game. Filters are a job for the team. Ductwork’s a job for us, unless you fancy a wrestling match with a stepladder.

Warning signs your system is overdue for a clean

These include grease dripping from hoods, lingering smoke or odours, weaker airflow, and a fan that sounds like it’s wheezing. Spot any of these before your next scheduled clean, and it’s worth acting on them straight away rather than waiting it out.

Keep an eye out for the following.

• Grease visibly dripping from hoods, vents or filters.
• Smoke or greasy odours that linger long after service ends.
• A noticeable drop in extraction airflow.
• The fan motor sounding louder or more strained than it used to.

There’s a technical side to this, too. A Wet Film Thickness Test (WFTT) measures the grease sitting inside your ductwork in microns. Anything over 200 microns means it’s time to book a clean; readings above 500 microns call for urgent attention.

The legal and financial consequences of non-compliance

Ignoring TR19 compliance can mean heavy fines, a shut kitchen, or an invalidated insurance policy, since fire safety law and your insurer both expect documented proof of regular cleaning.

Commercial kitchens operate under two key pieces of legislation.

1. The Health and Safety at Work etc. Act 1974
2. The Regulatory Reform (Fire Safety) Order 2005

Both place a legal duty on you to manage fire risk properly. An unannounced visit from an EHO can lead to enforcement action where fire or food safety risks are identified.

Here’s the part that catches people out. Without documented evidence of regular TR19 inspection and cleaning, insurers may reduce or reject claims if poor maintenance contributed to the loss. That paperwork is what stands between you and a very expensive conversation with your insurance provider.

Partner with us for peace of mind

Daily wiping keeps the surface tidy, but proper TR19 compliance needs a specialist clean. At KDC Food Hygiene Ltd, we handle the deep clean your extraction system actually needs, working efficiently around your service hours, so your kitchen isn’t sitting idle any longer than it has to be.

Once the job’s done, you’ll get a full BESA Post Clean Report and TR19 certificate, giving you the paperwork your insurer and EHO will want to see.

Get in touch today to get a quote. We’ll deal with the greasy bits, so you’ve got one less thing to worry about before the next inspection.

FAQs

How often does a commercial kitchen extraction system need cleaning?

Most systems need cleaning every three to 12 months, depending on how many hours the kitchen runs and what’s being cooked.

What are the TR19 cleaning intervals?

TR19 sets three intervals: every three months for heavy use, every six months for moderate use, and every 12 months for light use.

Can grease filters be cleaned in-house?

Yes. Metal grease filters can be removed and scrubbed weekly by kitchen staff, though the ductwork itself needs a professional deep clean.

How is a system checked for TR19 compliance?

A professional inspection measures grease deposits in microns. Anything over 200 microns means a clean is due, and over 500 needs urgent attention.

Do I need proof of extraction cleaning for insurance?

Yes. Insurers usually ask for a cleaning certification as evidence before paying out on a kitchen fire claim.