Questions To Ask A Plumber Before You Hire

Most plumbing surprises come from things nobody asked about up front: a permit that was never pulled, a fixture grade that changed, a wall left open, or a bill that grew because old pipe turned up behind the tile. You can head off most of that by asking good questions before anyone picks up a wrench.

This guide groups the questions by stage, from the first phone call to the final walk-through. Pick the ones that fit your job. A small repair needs only a few; a water heater replacement, sewer line repair, or repipe deserves the full list.

On The First Call

The first call is a quick filter. You are checking fit, not negotiating price.

1. Do you work in my town, and how soon could someone look at the problem?
2. Is this the kind of job you do often? Ask specifically about the work, such as tankless water heaters, sump pumps, or camera inspections of a sewer line.
3. Will a master or journeyman plumber do the work, or supervise it on site?
4. Do you charge for the visit or the diagnosis, and is that credited if I hire you?
5. Can you give me a written estimate before work begins?

If the answer to the last question is no for anything beyond a quick fix, that tells you something. Emergencies are different, but even then you can ask for the rate and how the bill will be figured before work starts.

Questions About The License And The Permit

Massachusetts makes this part simple. The state says only a master or journeyman plumber holding a license from its Board of State Examiners, working under permits from the local plumbing inspector, may do plumbing work at your home. Ask:

• What is your license number, and is it a master or journeyman license?
• If your company is a corporation or LLC, who is the master plumber on the business license?
• Does this job need a permit, and will you pull it before starting?
• When will the inspection happen, and do I need to be home for it?

Then check the answer yourself through the state's license lookup. The lookup lets you search by name, license number, license type, or business, so you aren't relying on a card or a sticker.

The local plumbing inspector must issue a permit before plumbing is installed, altered, removed, replaced, or repaired, and permits go only to plumbers who hold a license. Minor repairs, such as fixing a leaky faucet or clearing a blocked drain, are the exception.

Source: Mass.gov, Plumbers and gas fitters consumer fact sheet

A plumber who suggests skipping the permit is asking you to carry the risk. Unpermitted work can come up during a home sale, and nobody from the town has checked it.

Questions About The Estimate

The estimate is where most misunderstandings start or stop. Massachusetts consumer guidance says the agreement should list all work, the materials, rough and finish completion dates, permitting and inspections, and the warranty on materials and workmanship. Ask:

• Is this a fixed price for the defined job, or time and materials? If it's time and materials, what is the hourly rate and is there a cap?
• What exactly is included, and what is left out? Ask directly about permit fees, haul-away of old fixtures, and patching any wall or ceiling that gets opened.
• What happens if you find something unexpected, like corroded pipe or a cracked drain? Will you stop and give me a written change before doing extra work?
• Which brand, model, and size are you pricing, and is there a cheaper or better option worth considering?
• How long is this estimate good for?

Questions About Your House And Its Pipes

South Shore housing skews old. Weymouth's 2026 Housing Production Plan says almost two thirds of the town's housing was built before 1960, and Scituate's 2025 plan puts about three quarters of its housing before 1980. Older systems often mix materials from several eras, so these questions are worth asking during the site visit:

• What kind of supply and drain piping do I have, and what condition is it in?
• Is anything you see likely to fail soon, even if it isn't part of this job?
• Will this repair connect new material to old pipe, and how will you handle that joint?
• Are there code issues from earlier work that the inspector is likely to flag?
• For drain and sewer problems: would a camera inspection help before you recommend digging or replacing a line?

Good plumbers will tell you what they see without turning every visit into a sales pitch. Ask them to separate what must be done now from what you can plan for later. A short written note on the condition of your pipes is useful even if you don't act on it this year, because it gives the next plumber a starting point and helps you budget for the work ahead.

Extra Questions For Water Heaters

Water heaters carry real safety stakes. The state's plumbing board points out that an improperly installed part such as a temperature and pressure relief valve can lead to serious explosions and injuries. When you replace one, ask:

• Is the size right for my household, and why?
• Will you install a new temperature and pressure relief valve and discharge pipe?
• Does the venting or gas line need changes for the new unit, and who handles them?
• What does the manufacturer's warranty cover, and what does your labor warranty cover?

Our water heater repair and replacement page covers the signs that a tank is near the end of its life.

Questions About Payment

Massachusetts consumer guidance for plumbing jobs recommends paying on a percentage basis as the work progresses. Ask:

• How much is due before work starts, and what is it for?
• What are the payment milestones, such as after rough-in passes inspection and after fixtures are set?
• What forms of payment do you accept, and will I get an itemized invoice?
• Is any part of the final payment held until the final inspection passes?

Be cautious about paying most of the price before any work happens. A deposit for special-order fixtures can make sense; a large payment for labor that hasn't happened yet rarely does.

Questions About Insurance And Warranty

• Do you carry liability insurance, and can you send a current certificate?
• Will you ask me to sign a waiver of insurance for the permit? If so, why?
• How long is your workmanship warranty, and what does it cover?
• If something leaks after you leave, how do I reach you, and how fast do you usually respond?

When a plumber applies for a permit in Massachusetts, they sign that they carry liability insurance or present a waiver signed by the homeowner. You are entitled to know which one is happening on your job.

Questions About The Work Day Itself

• How long will the water or gas be off, and can you schedule around my household?
• Who will be on site, and will a master or journeyman be there the whole time?
• How will you protect floors and finishes, and who cleans up?
• Will you take away the old water heater, toilet, or pipe?

Questions To Ask Before You Pay The Final Bill

Final Walk-Through Checklist

• Show me what you replaced, and let me keep or see the old parts if I ask.
• Has the inspection passed, or when is it scheduled?
• Where is the main shutoff, and is there anything new I need to know how to operate?
• Does the invoice match the estimate, with any changes I approved in writing?
• Where is the written warranty, and whom do I contact if there's a problem?

If You Need Help Fast

When water is pouring through a ceiling, you won't get through this whole list. Ask the essentials: the license number, the rate, whether a permit will be filed, and when they can arrive. Our emergency plumbing guide covers what to do first. If you live in Brockton, the Brockton plumbing page has local permit and housing notes.

For the bigger picture of checking licenses and permits, read How To Hire A Plumber On The South Shore. When you're ready, South Shore Plumber Finder can connect you with an independent local plumber who serves your town, and you can put these questions to them directly.

Sources

• mass.gov/info-details/plumbers-and-gas-fitters-consumer-fact-sheet
• mass.gov/how-to/check-an-occupational-board-license
• mass.gov/orgs/board-of-state-examiners-of-plumbers-and-gas-fitters
• weymouth.ma.us/DocumentCenter/View/14032/Weymouth-Housing-Production-Plan---Fina
• scituatema.gov/DocumentCenter/View/12627/Housing-Production-Plan-2025

Written by the South Shore Plumber Finder editorial team for homeowners on the Massachusetts South Shore. This guide is general information, not legal advice. See our Editorial Standards.