Homeowner Checklists

1. Before you hire a duct cleaner

This checklist decides whether there is a job at all. The U.S. Environmental Protection Agency (EPA) does not recommend routine cleaning of heating, ventilation, and air-conditioning (HVAC) ductwork, only cleaning as needed, and the test it gives is a visual inspection.

• I have looked inside at least one supply duct and one return duct myself, because the EPA’s test for whether cleaning is needed is a visual inspection rather than a schedule or a season.
• I checked for substantial visible mold growth inside hard-surface ducts or on other HVAC components, which is the first of the three conditions the EPA says warrants considering cleaning.
• I checked for evidence of rodents or insects in the ductwork, which is the EPA’s second qualifying condition.
• I checked whether debris is actually clogging the ducts and being released into rooms from supply registers, which is the EPA’s third qualifying condition and is different from ordinary dust.
• I understand that dusty return registers alone are normal and do not by themselves indicate a contaminated duct system.
• If I found a moisture problem, I have identified its cause, because the EPA is explicit that underlying causes must be corrected or the problem will simply recur after cleaning.
• I am not buying this expecting a health benefit, since the EPA states duct cleaning has never been shown to actually prevent health problems, and that finding applies to every company in the trade.
• I have counted my supply registers and return grilles and know how many separate heating and cooling systems the house has, because every published pricing model rests on one of those counts.
• I know what my ducts are made of — bare sheet metal, fiberglass duct board, or internally lined — because that determines what may legally be applied inside them.
• I have a planning number before I take a quote. Published full-scope per-system cleaning runs $450 to $1,000, homeowner-reported spending clusters near $389, and our own planning range for a typical accessible single-system home is $300 to $700.
• I have checked what licensing, registration, or bonding my state or municipality requires, with the relevant authority directly, since requirements vary by location and no national credential tracks them.
• I plan to get at least two quotes and ask both companies identical questions, so that a price difference tells me something about scope rather than about salesmanship.

Full detail: whether you need duct cleaning at all.

2. Questions to ask a contractor

Ask these by phone, before anyone is inside your home. Each one has a good answer and a bad answer written out in full on our contractor question framework.

• Will you inspect the entire system before you give me a price, and if you quote by phone first, what assumptions is that number based on?
• Which components are included and which are excluded — supply ducts, return ducts, plenum, air handler cabinet, blower, evaporator coil, registers and grilles?
• Is cutting and properly resealing access openings included in the price, given that a duct system cannot be cleaned through the register openings alone?
• How is the price calculated — per system, per vent, per square foot, or hourly — and what is the rate for each additional vent if my count is wrong?
• Is the advertised price the price I will pay for my house, and will you put that number in a written estimate before you arrive?
• What equipment will be used, specifically whether the work uses negative pressure with a collection unit and mechanical agitation such as a rotary brush or air whip?
• Will you show me inside the system before you start and after you finish, with me present when any photographs are taken?
• Are you proposing any sanitizer, antimicrobial, or other chemical, and may I read the product label including its EPA registration number and the surfaces it is approved for?
• What is your full legal business name, and what license, registration, and insurance can I verify independently?
• What happens if you find something unexpected, and will you stop, show me, and quote it in writing before doing any additional work?
• How long will the job take? A Colorado attorney general action documented two to three hours advertised against five to eight hours actually required, so an implausibly short estimate is a scope signal.

3. Scam warning signs

Every item below traces to a state enforcement action, an attorney general warning, a Better Business Bureau study, or a verified news investigation. Items that circulate widely but that we could not trace to any such source — planted debris, cash-only demands, and the “$99 whole house” figure — are deliberately absent. Full case detail is on our air duct cleaning scams page.

• The whole-house price advertised is under about $70. Every documented enforcement case in our record involved an advertised price between $29 and $69, and each ended in bills over $1,000.
• The offer came from an unsolicited call, especially a recorded one. One Washington attorney general case documented more than 13 million robocalls, with caller ID spoofed across over 100 numbers using local-sounding company names.
• The advertisement discounts from a stated “regular” price. In both Washington and Oregon the companies were found never to have sold at the regular price their coupons claimed to discount.
• The offer states no vent count and no component list. One Denver company advertised $242 for a “whole house” job whose fine print limited it to 5 rooms and 10 vents.
• The scope excludes the air handler, blower, coils, or access openings. One Washington case involved advertising that omitted that only half the heating and cooling system was included.
• Mold or another dangerous substance is announced without a proper inspection. NADCA names this specifically as a red flag, and the EPA notes visual inspection alone cannot confirm mold.
• An add-on is offered with no written price. An Oregon complaint alleges the same UV light was sold at $40 to one customer and $775 to another, and that technicians were given a range to charge rather than a price.
• A sanitizing treatment is proposed and the technician will not show the label. No product is EPA-registered as a biocide for fiberglass duct board or fiberglass-lined ducts, and label-inconsistent use of a pesticide violates federal law.
• A multi-year membership or VIP plan is offered during the visit. One Washington case involved roughly $1,200 memberships that bought only annual visual inspections; a Northwest investigation documented $1,250 and $1,794 packages, one sent to collections.
• The reviews arrived in a burst. One Washington case documented roughly 100 fake five-star reviews posted within a single week.
• The social media account is a generic geographic name, newly created, or locked. The Michigan Attorney General lists these signals, including posts protesting that the service is not a scam.
• The legal entity cannot be confirmed. A Colorado action involved businesses reopening under new names after telling courts they had closed, and a 2025 North Dakota news account described a business two states could not identify as licensed.
• You are being pressed to decide while technicians are in your home. One homeowner in a Northwest investigation described being alone with her children and feeling “cornered and pressured.”

4. Before the technician arrives

• I have the written estimate in hand, naming the vent count, the component list, the total, and any per-vent overage rate.
• I have confirmed who is coming and, if certification was claimed, whether the assigned technician is the certified person.
• I have a copy of the insurance certificate and have confirmed it with the carrier rather than accepting a photocopy.
• I have taken my own photographs of one supply duct interior, one return, the air handler cabinet, and the area around it, so that before and after are mine and not only theirs.
• Furniture, rugs, and soft furnishings near registers are moved or covered. The Michigan Attorney General’s warning describes dirt blown onto drapes, carpets, and furniture as a hallmark of low-effort work.
• Every register and grille is physically accessible, since anything the technician cannot reach will either be skipped or become a reason to charge more.
• The air handler and the path to it are clear, including any attic, crawlspace, or closet access.
• A second adult is present if possible. In-home pressure at the moment of an unexpected finding is the single most consistently documented feature of the enforcement record.
• I have decided in advance what I will say to an upsell: that nothing extra is authorized today, and any recommendation should be emailed with a written price.
• I know that steam and other moisture-introducing methods should never be used on ductwork, so I will stop the work if one is produced.

5. After-service inspection

Do this before the technician leaves and before you pay, while questions can still be answered by the person who did the work.

• I looked inside the same duct sections I photographed beforehand and compared them, rather than accepting images taken outside my presence.
• Every component listed on the estimate was actually addressed, including the return ducts, which are the most commonly skipped part of the system.
• The air handler cabinet, blower, and coil were opened and cleaned if the estimate said so, and I saw them.
• Every access opening cut into the ductwork has been properly closed and sealed, not taped over temporarily.
• All registers and grilles are refitted and secure, and none are missing screws or left loose.
• No flexible duct is crushed, torn, or disconnected, since flexible duct is more easily damaged than rigid duct.
• There is no new dust film on furniture, drapes, or carpets near the registers, which is the visible signature of debris pushed into living space rather than collected.
• The system runs normally in both heating and cooling, checked before the technician leaves. One 2025 news account described a heating system failing within days of a duct cleaning visit.
• The final invoice matches the written estimate, and every line item that differs was approved by me in writing beforehand.
• Any chemical actually applied is named on the invoice, with the product name and EPA registration number recorded for my file.
• I have not signed a membership, service plan, or recurring agreement that I did not intend to buy when the day started.
• If something is wrong, I know the order of remedies: ask for it to be redone, then dispute the charge with my card issuer, then complain to my state consumer protection division and the Better Business Bureau.

6. Mold concern checklist

Use this the moment anyone says the word “mold.” It is also the checklist to use if you found something yourself. Background: mold in air ducts.

• I asked what the mold finding is based on. The EPA notes that visual inspection alone cannot confirm mold and that expert or laboratory analysis may be needed.
• I know that laboratory confirmation of whether a substance is mold costs roughly $50, which is small enough that a same-day remediation quote based on eyesight alone is not reasonable.
• I did not accept a mold diagnosis delivered without a proper inspection, which NADCA names as a common red flag in its own consumer guidance.
• I established what my ducts are made of first, because the correct response differs completely between bare sheet metal and fiberglass.
• I know that wet or moldy duct insulation cannot be effectively cleaned and, per the EPA, should be removed and replaced rather than treated.
• I know that once fiberglass duct liner is contaminated with mold, cleaning is not sufficient to prevent regrowth, so a cleaning-only proposal for lined duct does not solve the problem.
• I asked what the moisture source is. Condensation on cooling coils is a major factor in moisture contamination, and the EPA is explicit that underlying causes must be corrected or the problem recurs.
• I refused any biocide or antimicrobial application without reading the label, knowing that a small number of products are EPA-registered for bare sheet metal duct interiors and none are registered for fiberglass duct board or fiberglass-lined ducts.
• I declined any offer to seal or encapsulate contamination, since the EPA, NADCA, and two other industry bodies do not currently recommend routine sealant use for that purpose in any type of duct.
• I treated mold remediation as a separate service from duct cleaning, with its own contractor, its own scope, and its own price — published mold remediation figures span a twentyfold range and are not a duct cleaning add-on.
• I got the finding, the proposed work, and the price in writing before authorizing anything, rather than deciding while technicians waited.

What to do next

• The full hiring sequence — the reasoning these checklists compress.
• Good answers and bad answers — what to listen for when you ask question 2.
• The cases behind the warning signs — what regulators actually proved, state by state.
• Turn your vent count into a range — do this before the first checklist’s last item.

Sources & references

• U.S. Environmental Protection AgencyShould You Have the Air Ducts in Your Home Cleaned?Page last updated February 19, 2026The three qualifying conditions, visual inspection as the deciding test, the ~$50 laboratory mold confirmation figure, the position on wet or moldy insulation, and the $450-$1,000 per system figure unchanged since at least January 2021.
• U.S. Environmental Protection AgencyUse of Disinfectants and Sanitizers in Heating, Ventilation, Air Conditioning, and Refrigeration SystemsPage last updated July 17, 2026General hard-surface label claims do not authorize use inside HVAC systems unless the label specifically says so.
• National Air Duct Cleaners AssociationHow to avoid air duct cleaning scamsIndustry guidanceTrade association, not a regulator. Source for the mold-without-inspection red flag and cautions about low-cost whole-house specials that exclude major components.
• Washington State Office of the Attorney GeneralJudge orders $10 million in penalties in AG Ferguson's robocall lawsuitAugust 26, 2020Final penalty in the case that documented $29-$55 advertised prices, fictitious regular prices, ~$1,200 inspection-only memberships and roughly 100 fake reviews in a week.
• Oregon Department of JusticeState of Oregon v. US Air Ducts u2014 civil complaintFiled October 16, 2019, Multnomah CountyAlleges the same UV light sold at $40 and $775 and that technicians were given a range to charge rather than a price.
• Michigan Department of Attorney GeneralAG Nessel warns Michigan residents about air duct cleaning scamsDecember 12, 2023Dirt blown onto drapes, carpets and furniture, plus the social media red flags used in the warning-signs checklist.
• CBS News ColoradoBBB study finds bad advertising in air duct cleaning industryFebruary 27, 2013The $242 whole house advertisement limited in fine print to 5 rooms and 10 vents.
• CBS News ColoradoState shuts down several air duct cleaning companies for scammingNovember 25, 2013$35 advertised against charges up to $1,000, reopening under new names, and two to three hours advertised against five to eight actually required.
• KGW (TEGNA)Customers left with $1,000 bills after responding to air duct cleaning adInvestigation$1,250 and $1,794 VIP packages sold in home following $39 advertisements.
• Valley News Live (Fargo)Fargo man warns of alleged unlicensed duct cleaning businessJanuary 7, 2025Single-source account of a heating system failing days after a duct cleaning visit by an apparently unlicensed business.