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Extraction cleaning - the case
An extract fan does not usually fail with a bang. It clogs, labours, overheats and stops - and when it does, the kitchen stops with it. Set the cost of that against a regular clean and the comparison is not close.
The short answer
When grease builds up on an extract fan, it works harder, runs hotter and eventually seizes - and without a working extract fan, a commercial kitchen cannot ventilate and cannot safely trade. The cost is not just the emergency repair or replacement; it is the lost trading while the kitchen is down, done at a time you do not choose. Regular cleaning that keeps the fan free is a fraction of that.
How a fan seizes
The extract fan sits at the end of the run, pulling greasy air through itself day after day. Grease deposits on the blades and housing, and because it builds unevenly, it first throws the fan out of balance - which makes it vibrate, wear its bearings and draw more current. Left longer, the coating thickens, the motor labours against the load, runs hot, and eventually the fan stalls or the motor fails.
None of this is sudden. The fan gives plenty of warning - noise, vibration, weaker extraction, higher running cost - but because it is out of sight on a roof or in a plant space, the warning is usually missed until the day the extraction simply stops. By then the cheap fix has long passed.
Cost one
The immediate cost of a seized fan is that the kitchen stops. Commercial cooking depends on extraction to remove heat, smoke and fumes and to provide the airflow that gas safety requires; without a working extract fan, the kitchen is neither safe nor legal to run at volume. A fan failure is not an inconvenience to work around - it closes the cookline.
That lost trading is usually the biggest number in the whole event, and it lands at the worst time, because a fan overworked by grease tends to fail under load - in service, at the busiest moment, not on a quiet morning when it could be dealt with calmly.
Cost two
The repair itself is dearer as an emergency. A fan that has seized may need bearings, a motor or complete replacement, and sourcing and fitting that at short notice - out of hours, at speed, to reopen a closed kitchen - costs more than the same work planned. A fan kept clean and inspected either never reaches that point or is dealt with as scheduled maintenance rather than a crisis.
There can be collateral cost too. A fan that has run hot and out of balance for a long time may have damaged its mountings or the surrounding ductwork, turning a fan problem into a bigger repair. Grease that ran the fan to failure has usually been building elsewhere in the system as well.
Cost three
A grease-caked fan is not only a reliability problem - it is a fire risk. The fan runs hot, it sits in the greasiest part of the system, and the same combustible coating that seizes it is fuel. A fan is a classic ignition point for a kitchen extract fire, which is precisely the scenario the whole TR19 Grease regime exists to prevent.
So a neglected fan carries the reliability cost and the fire-and-insurance exposure at once. Keeping it clean addresses both: the fan keeps running, and the most dangerous part of the extract system is kept free of the fuel that would let a fire start there.
The comparison
Set it out plainly. On one side, regular cleaning that keeps the fan and the system free of grease - a modest, planned cost on a sensible cycle. On the other, a seized fan: lost trading while the kitchen is closed, an emergency repair or replacement, possible collateral damage, and a heightened fire risk throughout. Even discounting the fire, the reliability cost alone dwarfs the cleaning.
The fan is simply the part of the system where neglect shows up first and most expensively. Cleaning it on schedule, as part of a proper extract clean, is not an optional extra - it is the cheapest insurance there is against a closed kitchen.
Questions
It stops the extraction. Grease builds on the blades, throws the fan out of balance, makes the motor labour and overheat, and eventually seizes it - and without a working extract fan the kitchen cannot ventilate or safely trade.
The biggest cost is usually lost trading while the kitchen is closed, on top of an emergency repair or replacement that costs more done at short notice - and possible collateral damage to mountings or ductwork.
Yes - noise, vibration, weaker extraction and higher running cost. But because the fan is usually out of sight on a roof or in a plant space, the warning is often missed until the extraction stops.
Yes. The fan runs hot, sits in the greasiest part of the system, and the coating on it is combustible - making it a classic ignition point for a kitchen extract fire.
Regular cleaning of the whole extract system, the fan included, keeps it free of grease so it does not seize and does not become a fire risk. It is far cheaper than an emergency.
In a proper TR19 Grease clean, yes - the fan is part of the system cleaned canopy to discharge, precisely because it is where grease does the most damage.
We clean the whole extract system, fan included, so the part most likely to seize is kept free of grease.
