Questions to Ask Before Hiring a Plumber

Before you hire a plumber, ask twelve questions: about the license, who pulls the permit, whether sewer work gets a camera inspection before the quote, what grade of parts goes in your walls, and what the warranty says on paper. The answers matter less as trivia and more as a pattern. Plumbers who work clean and legal answer all twelve without flinching.

This is the plumbing companion to our general guide on how to choose a home services contractor in Seattle. Read that one for license lookups and red flags that apply to every trade. This one covers what is specific to plumbing.

Licensing, permits, and people

1. What is your plumbing contractor license number?

Why it matters: Washington requires plumbing companies to hold a plumbing contractor license, and the individual plumbers to be state certified. A general contractor registration is not enough. A good answer: the number is offered immediately, and it checks out on the L&I Verify a Contractor tool. Anyone who dodges this question is asking you to take an unverifiable risk with your water lines.

2. Will you pull the permit and schedule the inspection?

Why it matters: Water heater swaps, repipes, sewer repairs, and gas line work generally require permits, and the inspection is your independent quality check. Skipped permits surface later, usually during a home sale, when they are most expensive to fix. A good answer: yes, under our license, with the fee shown as a line item. Being asked to pull an owner's permit yourself is a red flag, not a favor.

3. Who actually shows up: a certified plumber or an apprentice?

Why it matters: Apprentices are part of every healthy trade, but they must be supervised, and the license holder is responsible for the work. A good answer: a certified plumber leads your job, and any apprentice on site works under supervision consistent with state rules. If the company cannot say who is coming, it cannot say who is accountable.

Technical judgment

4. For sewer work: will you camera the line before quoting, and do I get the footage?

Why it matters: Nobody can honestly price a sewer line repair without seeing inside the pipe. Quotes based on guesswork protect the plumber, not you, and scare-quotes based on nothing are a known abuse. A good answer: a camera inspection first, with the recording shared with you, including the distance counter so you can verify where the problem sits. If you are new to the term, our glossary entry on the sewer scope explains what the camera shows and why it matters in a region full of older clay and concrete side sewers.

5. What grade of parts do you install: supply-house or big-box?

Why it matters: The same faucet brand often sells different internals through retail stores than through professional supply houses. Cartridges, valves, and finishes differ, and so does lifespan. A good answer: explains the difference without being asked twice, tells you which grade is quoted, and offers options. A plumber who says all parts are the same has not paid attention or hopes you will not.

6. For water heaters: which code items are included in the price?

Why it matters: A legal water heater install in Washington involves more than swapping tanks. Expect a thermal expansion tank where required, seismic straps because this is earthquake country, a proper temperature and pressure relief discharge line, and in many cases a drain pan. Cheap bids skip these. A good answer: lists the code items unprompted and includes them in the number. Our page on water heater installation code covers what a compliant install looks like, so you can compare bids against it.

7. For a clogged drain: do you recommend snaking or jetting, and why?

Why it matters: Snaking punches a hole through a clog; hydro jetting cleans the pipe wall. Each has its place, and the honest recommendation depends on the pipe's condition and history. A good answer: asks about recurrence, considers the pipe material, and explains the tradeoff. Our comparison of hydro jetting vs snaking lays out when each one makes sense.

8. What happens if you open the wall and find more damage?

Why it matters: Old galvanized pipe, hidden corrosion, and past DIY repairs are common in pre-1980 Puget Sound houses. Discoveries are normal. Surprise invoices are not. A good answer: work stops, you see photos, and a written change order is approved before anything continues.

Money, warranty, and cleanup

9. Is this a flat-rate price or time and materials?

Why it matters: Both models can be fair, but you need to know which applies and what could move the number. A good answer: names the model and the specific conditions that would change the price. Open-ended hourly billing on a poorly defined job is how a faucet repair becomes a four-figure invoice.

10. What is your warranty on labor, separate from parts?

Why it matters: The manufacturer covers the tank or the fixture. Only the plumber covers the workmanship, and only if it is in writing. A good answer: a specific labor warranty term printed on the invoice, plus clarity about what the manufacturer covers and for how long.

11. Are you available for emergencies, and what do after-hours calls cost?

Why it matters: Pipes fail on weekends. If this plumber will not answer at 7 PM on a Saturday, you want to know now, not mid-flood. A good answer: plain hours, plain after-hours pricing, no surprises.

12. Who handles cleanup and hauls away the old equipment?

Why it matters: Disposal of an old water heater or cut-out pipe is real work, and bids differ on whether it is included. A good answer: included, stated in the scope, along with floor protection during the job.

Common questions

Does a dripping faucet really need a licensed plumber?

Simple like-for-like fixes are within reach of a careful homeowner, and an honest plumber will say so. The license question becomes critical when the job touches supply lines, drains, gas, or anything behind a wall. If a small repair reveals corroded shutoff valves or crumbling galvanized pipe, stop and call a professional.

Why do plumbing bids vary so much for the same job?

Almost always the scope. One bid includes the permit, code items, supply-house parts, haul-away, and a written warranty. The other includes a tank and two hours of labor. Line up the scopes item by item before you look at the totals, and most of the mystery disappears.

Is a permit really required just to replace a water heater?

In most Washington jurisdictions, yes. The permit exists because a bad water heater install can leak carbon monoxide, scald, or burst. The inspection typically takes minutes and confirms the code items from question six actually got installed. A plumber who calls the permit unnecessary is telling you how they work when nobody checks.

What to do next

Ask every bidder the same twelve questions and keep notes, because the pattern in the answers is the real bid. If you want to hear our answers, Eco puts the license number, scope, code items, and labor warranty in writing on every plumbing quote. Browse what we do on our services page, book online, or call (206) 970-1031, 6 AM to 6 PM every day.