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Duct cleaning - buying well
When one quote for cleaning your ductwork or extraction system comes in far below the others, it is worth asking why - because a price that low usually buys less work, not the same work cheaper. The gap has to come from somewhere, and it comes out of the parts of the job you cannot see. Here are the red flags to look for in a cheap cleaning quote, and what each one is quietly leaving out.
The short answer
A cleaning quote that comes in far below the others is usually cheaper for a reason: it is doing less. The work of properly cleaning a duct or extraction system - reaching the whole run, cleaning it to standard, and proving it was done - takes time, access and skill, and those cost money, so a price well below the market rate has usually cut some of them. The red flags are the tell-tale signs of that in the quote itself: no mention of cleaning the whole system (only the reachable parts), no post-clean certification or report (so no proof it was done to standard), no access provision (so hidden sections get skipped), a scope described vaguely (so it can mean whatever is convenient), and no evidence of competence or insurance. Each of those is a way the cheap quote is quietly narrower than it looks - cleaning less, proving nothing, and leaving the parts that matter most (the hidden, grease-laden runs) untouched. So the way to read a cheap quote is not by its price but by what it leaves out: a proper job specifies the whole system, access, cleaning to standard, and a report proving it; a cheap one goes quiet on exactly those. If the quote does not say it cleans the whole system and proves it, assume it does not.
Where the low price comes from
The first thing to understand about a very cheap cleaning quote is that the low price has to come from somewhere. Properly cleaning a duct or extraction system is real work: reaching the whole length of the run (including the hidden, awkward sections), cleaning it to a recognised standard, and documenting that it was done. That work takes time on site, the right access and equipment, and the skill to do it and prove it - and all of those cost money. So a legitimate quote reflects the cost of doing the whole job. A quote far below that is not usually the same job done more cheaply; it is a narrower job, because the price has been cut by cutting work. The gap between a cheap quote and a fair one is, in almost every case, the value of the work the cheap one is not doing.
This is why price alone is a poor way to choose a cleaner, and why a suspiciously low quote deserves scrutiny rather than celebration. The parts of the job most likely to be cut are the ones the buyer cannot easily see: the hidden sections of ductwork, the certification, the thoroughness of the clean. So the cheap quote can look like the others on the surface - it says it will clean your system - while quietly meaning far less. Reading a cheap quote well means looking past the headline price to what the quote actually commits to, because that is where the difference lives. The red flags below are the specific things to look for: the signs, in the quote itself, that the low price is buying a narrower job than it appears.
Red flag one and two
The first red flag is a quote that does not commit to cleaning the whole system. A grease extraction duct or a ventilation run has easy parts (the canopy, the reachable lengths) and hard parts (the vertical risers, the long horizontal runs, the sections behind other equipment) - and it is the hard, hidden parts that matter most, because that is where grease and dirt build up unseen and where the fire and airflow risk concentrates. A cheap quote often cleans only the easy, reachable parts and goes quiet on the rest, so the system looks cleaned (the visible bits are) while the hidden risk is untouched. If a quote does not explicitly say it cleans the whole system, end to end, assume it does not - and that the parts it skips are exactly the ones you most needed done.
The second, closely related, red flag is no provision for access. Cleaning the whole of a duct run means getting to all of it, which means access panels - either using the ones already fitted, or cutting and fitting new ones where the run is sealed. A proper clean includes reaching the whole system, so it includes the access to do so. A cheap quote that says nothing about access is usually planning to clean only what it can reach without any - which, in a system without enough access panels, can be very little. So no access provision is a sign the clean will stop wherever the ductwork closes up, leaving the sealed sections (often the dirtiest) alone. The presence or absence of access in the quote tells you how much of the system will actually be cleaned.
Red flag three and four
The third red flag is no post-clean certification or report. A proper clean of a grease extraction system is done to a recognised standard (TR19 Grease, in the UK), and it produces evidence: a report recording what was cleaned, photographs before and after, and measurements where relevant, which together prove the system was cleaned to standard on a given date. That evidence is not a nicety - it is what your insurer and your fire risk assessment rely on, and it is your proof the job was done. A cheap quote that includes no report or certification is not producing that proof, which usually means the clean is not being done to a provable standard. No report is a red flag both because you lose the evidence you need and because its absence often signals the clean itself is not to standard.
The fourth red flag is a vague scope - a quote that describes the work loosely (clean the ducting, service the extraction) without specifying what, how far, to what standard, and with what proof. Vagueness in a quote is not carelessness; it is flexibility, in the cleaner's favour. A vague scope can be satisfied by whatever is convenient on the day - a quick clean of the reachable parts - because it never committed to more. A proper quote is specific: it names the system, the extent (the whole run), the standard (TR19 Grease), the access, and the deliverable (a report). A cheap, vague quote leaves all of that open, which means you cannot hold it to anything and it can do as little as it likes. So specificity in a quote is a sign of a proper job, and vagueness a sign of a narrow one dressed up to look complete.
Red flag five
The fifth red flag is no evidence of competence or insurance. Cleaning a grease extraction or ventilation system properly is skilled work with real risks - working at height, in confined spaces, with the fire risk of grease - and it needs a competent, insured contractor. A proper cleaner can show their competence (training, accreditation, references) and their insurance (public liability, and cover appropriate to the work). A cheap quote from a contractor who shows none of this is a warning: it may be someone without the skill to do the job to standard, or without the insurance to cover the risk if something goes wrong - either of which is a false economy however low the price. So the absence of any evidence of competence or insurance is a red flag about who is doing the work, on top of the red flags about what work is being done.
Taken together, these five red flags - no whole-system scope, no access, no certification or report, a vague scope, and no competence or insurance - are the ways a cheap quote is quietly narrower than a fair one. None of them is about the price directly; all of them are about what the quote does and does not commit to. And that is the point: a cheap quote is cheap because it commits to less, and the red flags are how you spot the less. Reading them lets you see past the headline number to the actual job, and judge whether the low price is a genuine saving or a job so narrow it leaves your real risk - the hidden, grease-laden runs - untouched and unproven. Usually it is the latter, which is why the cheapest quote so often turns out to be the most expensive.
The takeaway
A cleaning quote far below the others is usually cheaper because it does less, and the difference comes out of the parts you cannot see - the hidden runs, the certification, the thoroughness. So the way to judge a cheap quote is not by its price but by what it leaves out. The red flags are the tells in the quote itself: no commitment to cleaning the whole system (so the hidden runs get skipped), no access provision (so the clean stops wherever the ductwork seals up), no post-clean certification or report (so nothing is proved and the clean is probably not to standard), a vague scope (so it can mean whatever is convenient), and no evidence of competence or insurance (so you do not know who is doing the work, or whether they are covered).
Each red flag is a way the cheap quote is narrower than it looks, and together they explain the low price: it is doing less, and proving nothing. So when a quote comes in far below the rest, do not take the saving at face value - read the quote for these flags. If it does not specify the whole system, the access, the standard, and a report, assume it is not doing them, and that the price reflects a job that leaves your real risk untouched. A proper clean says what it does and proves it; a cheap one goes quiet on exactly those points. The quiet is the red flag - and reading it is how you avoid paying twice.
Questions
It can be, if it commits to the same work as the others - the whole system, proper access, cleaning to standard, and a report - and simply prices it keenly. The problem is not a low price in itself but a low price that comes from doing less. So do not rule out the cheapest quote automatically; read it against the red flags. If it specifies everything a proper quote should and is still cheaper, that may be a genuine saving. If it is cheaper because it is quiet on scope, access, certification and competence, the saving is an illusion.
No post-clean certification or report. A proper clean of a grease extraction system is done to the TR19 Grease standard and produces documented proof - a report with before and after photographs. That proof is what your insurer and fire risk assessment rely on, and its absence usually means the clean itself is not to a provable standard. A quote that produces no report leaves you with no evidence the work was done properly, which is both a compliance gap and a strong sign the work was not done properly. If you check one thing, check that the quote includes a report.
Because the hidden ductwork is the hard, time-consuming part to reach and clean, and skipping it is the easiest way to cut the price. The vertical risers, the long horizontal runs and the sealed sections need access and time; the reachable parts do not. So a cleaner cutting corners cleans the visible parts - which makes the system look done - and leaves the hidden runs, which is exactly where grease builds up unseen and where the fire and airflow risk concentrates. The cheap quote skips the parts that matter most because they are the parts that cost the most to do.
A proper scope names the system, the extent (the whole run, end to end), the standard (TR19 Grease for a kitchen extract), the access to be used or fitted, and the deliverable (a post-clean report with photographs). A vague scope leaves those open - clean the ducting, service the extraction - so it commits to nothing specific and can be satisfied by whatever is convenient. If you cannot tell from the quote exactly what will be cleaned, how far, to what standard, and what proof you will get, the scope is too vague, and the vagueness usually favours the cleaner doing less.
Yes - and a proper contractor will provide them readily. Cleaning a grease extraction system is skilled, higher-risk work (at height, in confined spaces, with a fire risk), so a competent cleaner carries appropriate training or accreditation and public liability insurance, and can show both. A contractor who cannot, or will not, is a risk on two counts: the work may not be done to standard, and you may be exposed if something goes wrong on your premises. Asking is reasonable and quick, and the answer tells you a lot about whether the low price reflects efficiency or corners cut.
Not necessarily - sometimes a quote is thin because the cleaner is inexperienced, or quoted without seeing the system, rather than deliberately cutting corners. But the effect on you is the same: a job that leaves the hidden runs untouched and proves nothing is a poor outcome whether it was meant dishonestly or not. So treat the red flags as signals to ask more, not automatic accusations. A good cleaner will answer the questions and firm up the quote; one that cannot, or resists, is telling you the thin quote was thin for a reason you would not want to pay for.
We quote the whole system, the access, the standard and the report - so you can see exactly what you are buying, not just the price. Ask us for a clear, specified quote for your ductwork or extraction system.
