Guide · Timing & triggers · UK-Wide
Grease does not build to a diary date - it builds to how hard you cook. These are the six triggers that should override the calendar and tell you a deep clean is due now.
The short answer
A fixed annual date is the laziest way to schedule a deep clean, because grease does not build to a calendar - it builds to how hard you cook. These are the six triggers that should override the diary and put a clean in front of you:
None of these is subtle once you know to look for them. The mistake is treating them as background noise - the extractor is always a bit noisy, the corner always smells a little - when each one is the kitchen telling you the load has moved past what daily cleaning can hold.
Reading the signals
Visible grease is the easiest to dismiss and the most revealing. If a film returns to the wall behind the range within a day or two of being cleaned, the surface you can reach is only a fraction of what is coating the canopy throat and the first run of duct. What you wipe is the tip; what you cannot see is the reason it keeps coming back. The same logic runs through the hidden grease traps a daily wipe-down never reaches - the pattern on the visible surface is a proxy for the load in the places you have no line of sight to.
Smoke and haze that used to clear and now hang around after the last order point to extraction that can no longer move the air it was designed to. Grease narrows the duct, the fan works against a restriction, and the kitchen holds heat and vapour longer. Staff notice it as a stuffier room before anyone thinks to blame the ductwork. Filters that need degreasing twice as often as they did six months ago are the same message from the other end of the system.
Pests are the trigger nobody wants and the one that allows least delay. Rodents and insects are drawn to hardened grease and trapped food debris, so a sighting is rarely about the front of house being untidy - it is about harbourage building up in the parts of the kitchen that only a deep clean addresses. An EHO score that has slipped, or a re-inspection you can feel coming, is a trigger with a deadline attached, and the clean that answers it needs to be documented, not just done.
The sixth trigger is the one owners plan around rather than react to. A menu that shifts toward frying or chargrilling raises the grease load overnight; a seasonal peak concentrates months of cooking into weeks; and an insurance or lease review is a date on which someone will ask for evidence that the kitchen has been maintained. Where daily cleaning holds the line between deep cleans is covered in where the line sits between a deep clean and a daily clean, and the interval that keeps a top rating safe is set out in how often to deep clean to protect a five-star rating.
Here is the honest limit worth stating plainly. A trigger tells you to clean - it does not replace the routine that stops the trigger firing so often. A deep clean prompted by any of these six will reset the condition and give you documented evidence, but it cannot write your food safety system, run your daily checks or train your team to spot the next signal early. The clean is necessary. It is not, on its own, sufficient. Treat the trigger as the alarm and the routine as the reason the alarm rarely sounds.
Questions
No. The best-run kitchens deep clean on a risk-based interval so the triggers rarely fire at all. But if any of the six signals appear before your next scheduled clean, they override the diary - grease, weak extraction or pests do not wait for a date.
Immediately, and as part of a proper response. A single sighting usually means harbourage has built up in grease and debris behind the line, so it needs professional pest treatment and then a deep clean to remove what was feeding the problem - not one or the other.
It can be. If the fan is straining, the room holds heat and smoke longer, or filters re-grease far faster than they used to, the system is telling you the duct is restricted. That is a survey job, because the restriction sits where you cannot see it.
If the change raises the grease load - more frying or chargrilling - then yes. It resets the baseline for the new cooking style and is the natural moment to re-measure the interval, rather than carrying an old schedule into a heavier menu.
It resets condition and gives you documented evidence, but it is one part of the answer. The trigger tends to return if the daily routine and the interval behind it are not right - the clean handles the backlog, the routine keeps it from building again.
Phoenix Duct Clean · by the numbers
Tell us what you are noticing - the grease that comes back, the haze that will not clear, the score that slipped. We will survey it and clean to the evidence. No-obligation quote, UK-wide.