Negative keywords for HVAC, plumbing and electrical, and the customers each one can cost you
A negative keyword list for HVAC, plumbing and electrical that shows, next to each entry, the paying searches it would also block, and where each negative should sit when you sell more than one trade.
TL;DR
- HVAC negative keywords: block job seekers, do-it-yourself fixes and product shoppers. Leave price words, reviews, place names, equipment brands and trade words such as "commercial" off your negative list unless your own search terms show they never turn into calls.
- A negative you type into Google Ads is negative broad match unless you change it. It blocks any search that contains all of its words, in any order, so "how to" as a broad negative also blocks "how much does it cost to replace a furnace".
- Negatives don't cover plurals or synonyms. "job" does not block "jobs", and "cheap" does nothing about "affordable".
- The account-level negative list applies to the search and shopping inventory of Search, Performance Max, Shopping, Smart, App and Local campaigns. A word that is junk for HVAC, such as "car" from "car ac repair", also blocks "ev car charger installation" for your electricians.
- In the search-term samples from five accounts we run, published in our case studies, five searches asked a price. None of them was cut.
How does a negative keyword decide what to block?
Negative match types don't behave like the positive keywords with the same names. Google's page on negative keywords says negative broad match "is the default for your negative keywords". Under it, your ad won't show "if the search contains all your negative keyword terms, even if the terms are in a different order". Negative phrase blocks the words in the same order, and other words may be in the search as well. Negative exact blocks the same words in the same order, "without extra words". Google says you choose the type "by using the appropriate symbols" (Add negative keywords to campaigns). For keywords those are quotes for phrase and square brackets for exact (keyword matching options).
Here is one negative, "hvac jobs", under each type. The rows mirror the cases in Google's own example table, which uses "running shoes": the same words, an extra word, a different order, and a singular.
| Search | Broad: hvac jobs | Phrase: "hvac jobs" | Exact: [hvac jobs] |
|---|---|---|---|
| hvac jobs | Blocked | Blocked | Blocked |
| hvac jobs tampa | Blocked | Blocked | Shows |
| jobs in hvac | Blocked | Shows | Shows |
| hvac job openings | Shows | Shows | Shows |
The last row comes from a separate rule. "Negative keywords won't match to close variants or other expansions," and Google says you need to "add synonyms and singular or plural versions" yourself (About negative keywords). Casing and misspellings are covered automatically.
Three things follow for a contractor's account:
- A two-word broad negative is wider than it looks. Broad "how to" means "how" and "to" anywhere in the search. "how much to rewire a house" has both, and so does "how often to pump a septic tank", a search one of the accounts below chose to keep.
- A negative added from the search terms report is exact by default. Google says negatives added to a Search campaign from the report "are added as negative exact match" (search terms report ideas). That blocks the one search you ticked. "how to reset ac breaker" stops; "how do i reset my ac breaker" still gets through.
- Google's wording and its examples point different ways. The negative keywords page says the ad won't show "as long as all the keyword terms are included in the search in the same order", which read literally would block "how much to" with phrase "how to". Every phrase example it gives puts the words next to each other. Check your search terms a week after adding one.
Google adds two warnings. "If you use too many negative keywords, your ads might reach fewer customers" (About negative keywords). And a negative that overlaps one of your own keywords "will cause your ad not to show" (Add negative keywords to campaigns).
Where should each negative live?
A negative can sit on an ad group, a campaign, a shared list or the account. The reach is what matters:
- Account level (Admin → Account settings → Negative keywords) applies to search and shopping inventory in "Search, Performance Max, App, Shopping, Smart, and Local campaigns", up to 1,000 negatives (account-level negatives).
- Negative keyword lists (Tools → Shared library → Exclusion lists, per Add negative keywords to campaigns) apply to whichever campaigns you attach them to. Google allows 20 lists of up to 5,000 negatives each (negative keyword lists).
- Performance Max takes negatives on a specific campaign or at account level, and they apply to "Search and Shopping inventory only" (Performance Max).
Our rule, from the accounts we run: the account level is for words that are wrong for every trade you sell, such as "salary" and "diy". A word that is junk for one trade and a job for another goes on that trade's campaign. The rule assumes each trade runs in campaigns of its own. HVAC advertising with repair and replacement kept apart applies the same split inside one trade.
"plumber near me" shows why. In a Dallas account (Rescue Air) it was moved into plumbing's own budget as "the plumbing equivalent of the term the business runs on". In a Phoenix account (A.P.E.S.) it was cut from the septic campaign, because inside the septic geography it bought sewer-connected households. Put that same negative on the account level and it switches off the plumbing campaign's main search. More on two trades in one account: one ad budget for HVAC and plumbing.
The HVAC negative keyword list, and what each entry also blocks
Block means add it, in the match type shown. Check means run the click count further down first. Leave means don't add it unless your own search terms prove it never becomes a call. The middle column is our reading from the accounts we run, applied to Google's matching rules above.
Job seekers
| Negative | What it also blocks | Call |
|---|---|---|
| salary, salaries, apprentice, apprenticeship | Nothing a customer types, in the accounts we run | Block, broad, account level |
| jobs, job | "small electrical jobs near me", "plumber for small jobs" | Block hvac jobs and hvac job as broad pairs. For the other trades, phrase "plumber jobs" and "electrician jobs", since broad would block "plumber for small jobs". Never "electrical jobs". More on job-seeker negatives for electricians. |
| hiring | "hiring a plumber for a water heater", a buyer using the word | Leave |
Do-it-yourself and diagnosis
| Negative | What it also blocks | Call |
|---|---|---|
| diy, youtube | Little. "diy or hire a plumber" is someone deciding | Block, broad |
| how to (broad) | "how much does it cost to replace a furnace", "how much to rewire a house" | Never broad. Add the exact searches from the report |
| reset, troubleshoot | "ac won't reset after power outage", which is a service call | Check |
| parts | "parts and labor to replace ac compressor", a buyer pricing the job | Block phrases like "furnace parts store", not the word |
Products and retail
| Negative | What it also blocks | Call |
|---|---|---|
| portable | "portable generator transfer switch installation", electrical work | Phrase "portable air conditioner", safe at account level. Never the single word there |
| car, auto | "ev car charger installation" | Phrase "car ac" and "auto ac", safe at account level. Never the single words there |
| heater | "water heater", "heater not working" | Phrase "space heater" only |
| home depot, lowes | "home depot water heater installation", someone who wants it installed and hasn't picked who | Check |
Price words
| Negative | What it also blocks | Call |
|---|---|---|
| cheap, affordable | "cheap ac repair near me", price-sensitive buyers who still hire | Leave |
| free | "free estimate ac replacement", the way many replacement buyers ask for a quote | Check. Block specific phrases, not the word |
| coupon, discount, specials, financing | Shoppers comparing offers, and replacement buyers | Leave if you run offers or financing |
| cost, price, how much | The research end of your highest-ticket jobs | Leave. Send them to a page with a price range |
Reviews, places and brands
| Negative | What it also blocks | Call |
|---|---|---|
| reviews, best, top rated | "best plumber near me", "[your name] reviews", someone choosing whom to call | Leave |
| a town you don't serve, e.g. "fort worth" | "ac repair dallas fort worth", a metro name people in Dallas use too | Leave. Fix the map in location settings |
| trane, carrier, rheem, generac | "trane ac repair", "generac installer near me", owners of that equipment | Leave the brand. Block "trane manual" and the like |
| your company name | Your brand campaign, if it sits at account level | Non-brand campaigns only |
For place names, the tool is location targeting, not a negative: match your ad area to drive time.
Trade words that mark a segment
| Negative | What it also blocks | Call |
|---|---|---|
| commercial | "commercial plumber", light commercial work at a bigger ticket | Leave if you do any |
| mobile home | A segment some shops serve | Block only if no truck goes |
| apartment, rental | Landlords and property managers booking repeat work | Block "apartments for rent" as phrase |
| pool, solar, generator, septic | Work another trade in your building sells | That trade's campaigns only |
What five accounts cut and kept
Five of our case studies publish a sample of the search terms each account was buying, with the verdict and the reason. That is 25 searches across the Tampa, Dallas and Phoenix accounts behind Comfort Authority, Rescue Air, Reeis, Cody & Sons and A.P.E.S.:
- Price searches: 5, none cut. "tankless water heater cost", "hvac service contract cost" and "leach field repair cost" were kept. "electrical panel upgrade cost" was moved to a page that answers the cost question, and "water heater flush cost" to a plan page with both prices on it (publishing a price range).
- Searches naming a place: 6. Two were cut, "hvac jobs tampa" and "electrician salary arizona", for the job-seeker word, not the place.
- Do-it-yourself and diagnosis questions: 4. Three were cut. The septic question was kept, because "the people asking it own the thing".
- Job seekers and product shoppers: 3, all cut.
- Brand: 1, kept. The company's own name: "Cheap, converts".
- "free": 1, cut, in an account selling maintenance plans, where "the word free selects for the one customer a plan cannot survive". That is a verdict about a subscription, not about replacement quotes.
Reeis Air Conditioning, Plumbing & Electrical, Phoenix. Electrical had been added to an account built for air conditioning and was buying emergencies, planned work and diagnostic searches at one bid. Electrical got its own campaign, diagnostic and career searches came out, and "electrical panel upgrade cost" went to a page that answers the cost question. Spend on terms that never called: −29%. Window: 90 days against the 90 before. Source: Google Ads.
Limit: Cutting the diagnostic searches removes future customers as well as non-customers. We accepted that trade at this budget and it would be the wrong trade at a much larger one.
How many clicks before "never called" means anything?
In the accounts we run, most rows in the search terms report carry a handful of clicks, and a row with no call proves little. The chance that a word gets zero calls by luck alone is (1 − your click-to-call rate) raised to the number of clicks: one factor of it for every click.
As an illustration, say 1 in 10 clicks in a campaign becomes a call. A word with 12 clicks and no call would come up empty by chance 28% of the time (0.9¹²). It takes 29 clicks before that drops under 5% (0.9²⁹ ≈ 4.7%). At 1 in 20, it takes 59 clicks.
So judge a word, not a row: add up every search in the report that contains it. If it clears the click count with no calls, block it. If it doesn't, you are deciding on meaning. Remember that the report leaves out "search terms that don't have enough query activity" (search terms report), so your totals run short.
What this doesn't cover
- How representative the case samples are. The 25 searches were chosen to illustrate each case study, not drawn at random. They show how we decided, not how often each kind of search books.
- Display and Video. Google says negatives "work differently" there (About negative keywords), and every negative is treated as broad (Add negative keywords to campaigns). This article is about Search and the search side of Performance Max.
- Local Services Ads. Not covered here. How they differ from Search ads is.
Do this in your account
- Collect what you already have, noting where each negative lives and its match type. Account level: Admin → Account settings → Negative keywords, then the download icon in the upper right corner. Campaigns: Keywords → Negative keywords, then the download button above the table. Shared lists: Tools → Shared library → Exclusion lists.
- Check every broad negative against the list above, starting with the account level. A blocked word has no search terms to count, so move any price, review, place, brand or trade word down to campaign level, leave it off one campaign for two to four weeks, and run the click count on what comes through.
- Move trade-specific negatives down to the campaigns of the trade they are junk for.
- Add the plurals and synonyms of the negatives you keep: job and jobs, career and careers.
- Read the search terms every two weeks. Campaigns → Insights and reports → Search terms, sorted by cost. Add junk from there, remembering it lands as exact.
The full half-hour account check, with search terms as one step, is in the Google Ads checklist for contractors. More on running the account is in the Google Ads articles for contractors.
FAQ
What negative keywords should an HVAC company use? Start with job-seeker words (salary, apprentice, hvac jobs as a broad two-word negative) and do-it-yourself words (diy, youtube), plus product phrases like "portable air conditioner". Add the rest from your own search terms report, not from a downloaded list.
Should I add "cheap" and "free" as negative keywords? Not as single words. In the samples from our case studies no price search was cut, and the one "free" search that was cut, "free ac inspection", was cut to protect a maintenance plan offer, not replacement quotes. Block a specific phrase once its click count shows it never books.
What is the difference between negative broad, phrase and exact match? Broad blocks a search with all the words in any order. Phrase blocks the words in the same order, even with other words in the search. Exact blocks only those words, in that order, with nothing added.
Do negative keywords work in Performance Max? Yes, on a specific campaign or at account level. Google says they apply only to Search and Shopping inventory.
How many negative keywords can I add? 1,000 at account level, and 20 shared lists of up to 5,000 each. Google's pages cited here don't state a limit for negatives added directly to a campaign or ad group. Google also warns that too many negatives can mean your ads reach fewer customers.
Sources
All read in full on September 24, 2026. Every quotation above is from these pages or from the case studies linked in the text.
- Google Ads Help, "About negative keywords", https://support.google.com/google-ads/answer/2453972
- Google Ads Help, "Add negative keywords to campaigns", https://support.google.com/google-ads/answer/7102995
- Google Ads Help, "About account-level negative keywords", https://support.google.com/google-ads/answer/11396330
- Google Ads Help, "About negative keyword lists", https://support.google.com/google-ads/answer/2453983
- Google Ads Help, "Negative keywords in Performance Max campaigns", https://support.google.com/google-ads/answer/15726455
- Google Ads Help, "Get negative keyword ideas using the search terms report", https://support.google.com/google-ads/answer/7102466
- Google Ads Help, "About the search terms report", https://support.google.com/google-ads/answer/2472708
- Google Ads Help, "Edit, remove, or download negative keywords", https://support.google.com/google-ads/answer/7102298
- Google Ads Help, "About keyword matching options", https://support.google.com/google-ads/answer/7478529