What should I ask before hiring a plumber?
Three questions filter out 90% of bad plumbing hires: Is your license current in this state? Will you itemize parts and labor separately? What evidence will you show me before expanding scope? A plumber who can't answer all three clearly isn't worth scheduling.
Lump-sum invoices and undocumented scope expansion are the two biggest plumbing scams. Getting itemization upfront and demanding camera footage before any line-work is approved is how you stay in control of the job.
The questions that separate pros from problems
Are you licensed and insured in this state?
License lookup: freeGood answer sounds likePlumbing is licensed in all 50 states — a master or journeyman license is required for most work beyond simple fixture swaps.
Walk away if…Ask for the license number and look it up on your state contractor board site before they arrive. Unlicensed work voids permits and can affect homeowner's insurance.
Will you itemize parts and labor on the invoice?
Saves $100–$400+ on a typical repairGood answer sounds likeLump-sum quotes hide 3–5x parts markups that are common in the trade. An honest plumber can tell you roughly what the part costs wholesale.
Walk away if…Ask for a written quote with line items before work starts. If they refuse, that's your answer.
What's your diagnostic process before recommending a repipe or main line replacement?
Camera inspection: $300–$600Good answer sounds likeFull repipes for a pressure problem are a common oversell. A failing pressure-reducing valve (PRV) mimics whole-house issues and costs $150–$400 to fix — not $8,000–$20,000.
Walk away if…Legitimate plumbers test the PRV and run a camera inspection before recommending major line work. Insist on seeing the footage.
Do you pull permits for this type of work?
Permits: $75–$300 — worth every centGood answer sounds likeWater heater replacements, gas line work, and new drain runs require permits in almost every jurisdiction. Unpermitted work fails home inspections at resale.
Walk away if…Ask which permits are required. If they say 'we skip it to save you money,' that's a red flag — the savings come back as a problem at closing.
Is the diagnostic fee credited toward the repair?
$75–$150 diagnostic, credited or notGood answer sounds likeMost plumbers charge $75–$150 for a service call. Many credit it toward the repair — some don't. It's a tell about how the business operates.
Walk away if…Ask before scheduling. If they say no, at least you know. If they say yes, get it in writing.
What's the after-hours or weekend rate?
After-hours add: $100–$300 extraGood answer sounds likeEmergency plumbing rates run 50–100% above standard. For anything that can wait until business hours, the savings are real.
Walk away if…Ask the rate multiplier upfront. A burst pipe warrants emergency pricing. A slow drain does not.
Before you even call
- Look up the plumber's license number on your state contractor board website before they arrive — it takes two minutes and confirms they're active and bonded.
- Write down every symptom: when it started, which fixtures are affected, and whether anything changed recently (new appliance, recent freeze, etc.). The more specific you are, the faster the diagnosis.
- Take photos or short videos of the problem area — standing water, staining, the location of shutoff valves — so the plumber can assess before opening walls.
- Know where your main water shutoff is before the plumber gets there. In an emergency, the first five minutes matter.
Unlock the hiring checklist
Use this before you call a plumbing, so you know what to ask and what to avoid.
Red flags that end the conversation
- Any plumber who recommends a full repipe without first testing the PRV or running a camera inspection — get a second opinion before approving anything over $1,500.
- Scope keeps expanding after they open the wall without showing you documented evidence (photos, camera footage) of what they found.
- They refuse to provide an itemized quote and only offer a single lump-sum number.
- They suggest skipping permits 'to save you money' on a water heater, gas line, or main drain replacement.
About pricing
Plumbing quotes should always be itemized — parts listed separately from labor. For any job over $500, ask whether the repair addresses the root cause or just the symptom (e.g., replacing a water heater without flushing sediment-clogged lines). Main line work should always come with camera footage before and after. Contingency costs (rotted subfloor, hidden cast iron) should be disclosed as a range, not discovered after demo.
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Related questions
Do plumbers need to be licensed for basic repairs?
Yes — plumbing is licensed in all 50 states. The license level varies (master vs. journeyman) and some minor fixture work has exemptions, but any job involving new pipe runs, gas connections, or water heaters requires a licensed plumber in most jurisdictions. Always verify on your state contractor board's website.
How much of a deposit should a plumber ask for upfront?
For standard repairs and service calls, no deposit is typical — they invoice after the work. For large jobs (sewer replacement, whole-home repiping), a deposit of 25–33% is reasonable. More than 50% upfront on a job that hasn't started is a red flag.
How do I verify a plumber's insurance?
Ask for a certificate of insurance (COI) showing general liability and workers' compensation. The COI should name your state and have a current expiration date. You can call the insurer on the certificate to verify it's active — takes five minutes.
Should a plumber guarantee their work?
Reputable plumbers warrant their labor for at least 1 year and pass along manufacturer warranties on parts. Get the warranty terms in writing before work begins. 'We stand behind our work' without a specific time frame is not a warranty.