Boolean search strings for plumbers: journeyman and master, service or new construction, backflow and medical gas

A plumber search needs two blocks that a bare title skips: the license level (apprentice, journeyman or master, with names that vary by state) and the setting (residential service, new construction, commercial or industrial). Endorsements narrow it further, because backflow testing, medical gas installation and drain and sewer work each describe a different slice of the trade. As of November 2026, LinkedIn supports capitalized AND, OR and NOT with quotes and parentheses, and Indeed's own trades guide shows the skill: field and location written as "lives in" a city inside the string.

Below are ten strings by license level and setting, and what Indeed, LinkedIn and Google support as of November 2026. For electrical trades at the same contractors, see Boolean search strings for electricians; for the operators themselves, see Boolean search strings for recruiters.

License levels, settings and endorsements that change what a plumber search finds

• License names vary by state. The Texas State Board of Plumbing Examiners, for example, lists Apprentice Registration, Tradesman Plumber-Limited, Journeyman Plumber, Master Plumber and Responsible Master Plumber among its license types, with a public license search, as of November 2026. Other states and some cities use their own titles and rules, so ask the client which license the job legally needs and check it with that board. This is not legal advice.
• Setting narrows more than license. Service plumbers write about drain cleaning, water heaters, repipes and leak detection; new construction plumbers about rough-in, top-out and trim; commercial plumbers about grease traps, backflow and larger buildings. Name the setting in its own block.
• Endorsements are specific. ASSE's professional qualifications standards list 5110 for backflow prevention assembly testers and 6010 for medical gas systems installers, and its backflow certification page covers the tester program. Add them only when the role needs that work.
• Lead-safe work matters on older homes. EPA's Renovation, Repair and Painting program requires firms paid to disturb painted surfaces in homes, child care facilities and preschools built before 1978 to be certified, with work done by or under certified renovators. Residential remodel plumbers often list it.
• OSHA cards are training, not a license. OSHA's Outreach Training Program page says none of its courses is considered a certification and that the program is voluntary. Use OSHA 10 or 30 as an optional term unless the client's site rules require a card.

Ten Boolean strings by license level and setting

Swap in the license level, setting and city from your own intake; these are examples.

Service and residential

1. Journeyman service plumber — Indeed Smart Sourcing
("journeyman plumber" OR "service plumber" OR "plumbing technician" OR "service technician") AND skill: ("drain cleaning" OR "water heaters" OR "leak detection" OR repipes) AND (licensed OR journeyman) NOT ("plumbing supply" OR estimator OR dispatcher)

2. Drain and sewer technician — Indeed Smart Sourcing
("drain technician" OR "sewer and drain technician" OR "drain cleaning technician" OR plumber) AND skill: ("hydro jetting" OR hydrojetting OR "camera inspection" OR "sewer line") NOT (dispatcher OR "customer service")

3. Apprentice close to licensure — LinkedIn general search
("apprentice plumber" OR "plumbing apprentice" OR "plumber apprentice") AND ("4th year" OR "fourth year" OR "5th year" OR "fifth year") NOT (helper OR laborer)

New construction and commercial

4. New construction plumber — LinkedIn general search
(plumber OR "journeyman plumber" OR "construction plumber") AND ("rough-in" OR "rough in" OR "top out" OR "trim out") AND ("new construction" OR "multi-family" OR "ground up") NOT ("plumbing supply" OR estimator)

5. Master plumber who pulls permits — LinkedIn Recruiter, Job titles + Keywords filters
("master plumber" OR "responsible master plumber" OR "plumbing contractor") AND (permits OR "pulled permits" OR inspections) AND (commercial OR residential)

6. Commercial plumber with backflow testing — Indeed Smart Sourcing
("commercial plumber" OR "journeyman plumber" OR plumber) AND skill: ("backflow testing" OR "backflow prevention" OR "grease traps") AND ("asse 5110" OR "backflow certified" OR "backflow tester")

7. Medical gas installer — LinkedIn Recruiter, Keywords filter
(plumber OR pipefitter OR "medical gas installer") AND ("medical gas" OR "med gas") AND ("asse 6010" OR hospitals OR healthcare)

8. Plumbing foreman or superintendent — LinkedIn Recruiter, Job titles filter
("plumbing foreman" OR "plumbing superintendent" OR "plumbing supervisor" OR "lead plumber") AND (commercial OR "multi-family" OR "new construction") AND (crew OR crews OR scheduling OR "material takeoffs")

Search-engine X-ray

9. Public profiles by license level and city — Google X-ray
site:linkedin.com/in ("journeyman plumber" OR "master plumber") "houston" -jobs -recruiter -supply

10. Public resumes with service work — Google X-ray, filetype search
filetype:pdf ("journeyman plumber" OR "master plumber") resume ("backflow" OR "water heaters") -template -sample

Many strong plumbers have thin online profiles or none, so both X-rays reach a smaller and older pool than a job board does. Treat what they return as leads, and verify the license before you submit anyone.

What Indeed, LinkedIn and Google actually support

Indeed's repair, maintenance and installation guide documents AND, OR, NOT, quotes and parentheses, a skill: field for the skills section and fieldofstudy: and school: for education, and its examples write location as "lives in" a city, as of November 2026. Its examples cover mechanics, electricians, carpenters, welders and HVAC technicians rather than plumbers, so the Indeed strings above follow the same pattern. Plumbers are more likely to have a job-board resume than a detailed LinkedIn profile, which is why most service strings here are written for Indeed.

LinkedIn's Boolean help page requires capital AND, OR and NOT, supports quotes and parentheses, and does not support wildcards, so "plumber" and "plumbing" both need writing out, and "rough-in" and "rough in" go in as a pair. LinkedIn Recruiter's Boolean page lists Job titles among its Boolean filters and warns that too many facets in one query can cause a search result issue. Google's search operators page documents quotes, site:, the minus sign and filetype:, but not OR, so test the OR block in an X-ray before relying on it.

Narrowing by service area, on-call and seniority

Plumbing is on-site work, and service plumbers drive a company truck to calls, so the service area matters more than a radius. List the metro and two or three surrounding towns, because many plumbers list the shop's city rather than their own. On-call and emergency rotations are not searchable but decide many offers; raise them on the first call.

Seniority shows in scope words: "ran my own truck," "lead plumber," "pulled permits," "trained apprentices" and "passed inspections," over "assisted," "helper" and "material runs." LinkedIn's page on premium search filters lists Years of Experience as a Recruiter and Sales Navigator filter; on Indeed or a basic account, a phrase such as ("licensed since" OR "years licensed") only finds people who wrote it.

False positives worth excluding with NOT

• Supply house staff. Counter sales and outside sales at plumbing supply houses mention fixtures and water heaters all day. Exclude "plumbing supply" and "counter sales."
• Office staff at plumbing companies. Dispatchers, customer service representatives and estimators work for plumbing contractors without doing the work. Exclude each by title.
• Plumbing engineers and designers. MEP designers write plumbing constantly, and ASPE's Certified in Plumbing Design (CPD) is a design credential. Exclude "plumbing engineer," "plumbing designer" and mep.
• Inspectors. Plumbing inspectors enforce the code rather than install to it. Exclude inspector unless the client is hiring one.
• Related trades. Pipefitters, steamfitters and sprinkler fitters overlap on piping; HVAC technicians overlap on water heaters and boilers. See Boolean search strings for HVAC technicians for that trade.
• Helpers and laborers, for licensed roles. "Plumber's helper" and laborer profiles list tasks without a license. Exclude them for journeyman and master searches.

None of these strings targets or excludes anyone by age, sex, race, religion, national origin, disability or veteran status, and yours should not either. Union status is not a search term either: the NLRB lists refusing to hire or consider applicants because of their union membership, activities or sympathies as unlawful discrimination.

A worked example: three passes on a service plumber search

An invented search, shown as it actually gets narrowed.

The license block found journeymen; the diagnostic block found service plumbers. A service company is usually hiring the second.

What a search cannot verify

A string can find someone whose profile names the right license level, setting and endorsement. It cannot confirm the license is active in the job's jurisdiction, show whether they work cleanly in a customer's home, or tell you how they handle an inspection that fails. The plumber screening questions test license level, setting and endorsements, the plumber job description template pins down service or construction before you search, and the interview guide for skilled trades covers later rounds.