Questions to ask a plumber before you hire

Updated · KeystoneProGuide editorial team

Why ask questions at all?

Because the answers are the only way to compare plumbers who quote different things. Most of the questions below come straight from a rule or a piece of official advice, and each one has the reason beside it. Ask them on the phone or at the estimate, and get the important answers on paper.

What should you ask about the plumber?

  • Which local license do you hold, and from which office? Pennsylvania has no state plumbing license, so the answer should name a city, township or borough. Confirm it with that office.
  • What is your Pennsylvania home improvement registration number? The Attorney General's office says master plumbers who repair or install plumbing in private homes must register, and the number must appear on estimates and contracts. Look it up in the state's contractor search.
  • Who will actually do the work? A company may send a journeyman or an apprentice. Fixr notes that when an apprentice comes, you usually pay the supervising plumber's rate, so ask who is supervising.
  • Can you send me a current certificate of insurance? Lower Merion Township's advice is to always request a current certificate, because policies expire at different times of year.

What should you ask about the price?

  • Is this a flat rate or by the hour? Angi says most plumbers bill by the hour but that flat rates are common for routine jobs such as clearing a drain or fixing a running toilet.
  • Is there a service call fee, and is it credited to the repair? Angi says nearly all plumbers charge a call fee. Know the amount before the truck arrives.
  • Are materials included? The Better Business Bureau suggests asking whether an estimate is a flat rate that includes materials or charges them separately.
  • What would make the price go up? Angi says costs rise when walls or floors must be opened to reach pipes, and that emergency visits cost 1.5 to 3 times the normal rate. Ask what happens to the price if the job turns out bigger.
  • If this is time and materials, what is the written estimate? Pennsylvania's home improvement law allows time-and-materials contracts only with a written initial estimate, and caps the bill at 10% above it unless you sign a change order.
  • Does the price include hauling away the old fixture or heater? HomeAdvisor says haul-away fees run $50 to $200 and are usually in the estimate; check that they are.

What should you ask about permits and inspections?

  • Does this job need a permit, and will you file it? The Federal Trade Commission lists a contractor who asks you to get the permits among the signs of a scam.
  • Who arranges the inspection? In Philadelphia, for example, a licensed master plumber must oversee permitted work, the inspections on the permit must be passed, and a Certificate of Approval follows. Ask what the inspector will check and when.

What should you ask about parts?

  • Will you install a fixture I buy myself? The BBB says some plumbers will not, and that if a part you supplied fails, fixing it may be on you.
  • What brand or grade of pipe will you use, and why? Material changes the bill: Angi gives copper at $4 to $12 a linear foot and PEX at $1.50 to $4. Ask for the material in writing.

What should you ask about a water heater?

  • What size do I need? ENERGY STAR suggests starting from the gallon capacity on the old heater's nameplate or yellow EnergyGuide sticker, and going up only if your household or fixtures have grown.
  • Where will the relief valve discharge? The residential code requires a temperature-and-pressure relief valve and a discharge pipe that ends no more than 6 inches above the floor or a drain, where you can see it, with no valve or tee fitting on it.
  • Does it need a drain pan here? The same code calls for a pan where a leaking tank would cause damage, though a replacement heater does not need a pan drain where there was none before.
  • For a heat pump model: is there enough space and air? ENERGY STAR says these units need a space that stays between 40 and 90 degrees year-round with 1,000 cubic feet of air around them.

What should you ask about a sewer or drain diagnosis?

  • Can I see the camera footage or photos of the defect? The Pennsylvania Attorney General's October 2026 settlement over unnecessary sewer replacements requires the company involved to document the defects behind any replacement it recommends. That is a fair thing to ask of anyone.
  • Did you try to clear the line first? The same order requires multiple attempts with a snake before excavation is sold, and requires telling customers they can get a second opinion.

What should you ask about water treatment?

  • Was my water tested by an independent lab? Penn State Extension says free hardness tests from softening companies are common, but a third-party test will protect you from being oversold.

What should you ask about the contract and payment?

  • Will I get a written contract with the dates, the total price and my cancellation notice? For jobs over $500, Pennsylvania requires all of these.
  • How much is due up front? The FTC advises against paying the full amount in advance. For larger jobs the Attorney General's office says about one-third down is generally appropriate.
  • What does your warranty cover, in writing? Ask for it on the contract, not on the phone.

How to choose a plumber explains how to check the answers, the cost guide gives the price ranges, and plumbers in the area are listed on the plumbers directory page.

Sources

  1. Frequently Asked Questions: Home Improvement Contractor Registration, Pennsylvania Office of Attorney General
  2. Home Improvement Contractor Search, Pennsylvania Office of Attorney General
  3. Licensed Contractor List, Lower Merion Township
  4. How Much Does Plumbing Repair Cost? [2026 Data], Angi
  5. How much does it cost to hire a plumber?, Fixr
  6. BBB Tip: Hiring a trusted and verified plumber can save you time and heartache, Better Business Bureau
  7. How To Avoid a Home Improvement Scam, Federal Trade Commission
  8. Get a Plumbing Permit, City of Philadelphia
  9. Heat Pump Water Heaters, ENERGY STAR
  10. Chapter 28 Water Heaters, 2021 International Residential Code, International Code Council
  11. AG Sunday Obtains Settlement Requiring Home Improvement Group to Pay Consumer Restitution and Undergo Robust Technician Certification Programs, Pennsylvania Office of Attorney General
  12. How Much Does a Plumber Cost in 2026?, HomeAdvisor
  13. Water Softening, Penn State Extension

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