Trade guide

Plumbing

Fixtures, water heaters, supply repipes and drain lines. Leaks hidden in walls can cause major damage, so good work and testing matter.

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What the work involves

  • Shutting off and draining the system
  • Replacing fixtures, valves and supply lines
  • Water heater replacement with proper venting and safety valves
  • Repiping supply lines (e.g., PEX or copper)
  • Drain, waste and vent work
  • Pressure testing and leak checks

What should happen, step by step

Use this as a checklist while the job is underway. If a step is skipped, ask why.

Durations are typical planning ranges from Corky's field experience, not guarantees. Weather, inspections, material lead times and surprises behind walls change them.

How long it usually takes

Fixture swaps and water heaters are often done in a day. Repipes and drain replacements can take several days plus wall and floor repair.

Plan your dates with the Project Timeline Planner

General guidance only. Your contractor's written schedule is what counts.

Inspections to expect

  • Underground / under-slab plumbing inspection
  • Rough-in (drain-waste-vent and supply) with pressure test
  • Water heater inspection (venting, relief valve, gas)
  • Final plumbing inspection

Which inspections apply depends on your city or county. Ask your contractor to share each passed inspection result. Understanding permits & inspections

What a good bid includes

Check off each item on the bids you receive:

How to read a bid · Have one in hand? Second Look Review (from $25)

Payment schedule

Service calls are paid on completion. Projects: deposit, payment after rough inspection, balance after final.

  • Pay a modest deposit, then progress payments tied to finished, visible milestones (e.g., 'rough-in passed inspection'), never to dates alone.
  • Keep payments at or behind the work completed - you should never have paid for much more than has been done and delivered.
  • Hold the final payment until the final inspection is passed, the punch list is finished and you have lien waivers.
  • Avoid cash. Pay by check or card so there is a record, and get a receipt for every payment.
  • Deposit limits vary by state: California, for example, caps a home improvement down payment at 10% of the price or $1,000, whichever is less. Arizona has no single statewide percentage cap that we are aware of, so negotiate it and put it in the contract. Check your state's rules.

Payment schedules & lien waivers

Red flags & common rip-offs

  • Scare tactics about needing a full repipe with no camera or pressure evidence
  • No permit for a water heater or repipe
  • No pressure test
  • Cheap no-name fixtures swapped in for what you picked
  • Pricing that hides drywall repair
  • Water heater with no relief valve discharge line
  • No test before closing walls

Also watch for the general warning signs: large upfront payments, cash-only, no written estimate, pressure to sign today and no proof of license or insurance.

Questions to ask before you sign

  1. What evidence shows this is needed (photos, camera inspection)?
  2. Who pulls the permit and schedules inspection?
  3. How will you test for leaks?
  4. Is wall and ceiling patching included?
  5. What brand and model of fixtures/heater will you install?
  6. Where are my main and fixture shutoffs, and will you label them?
  7. Is an expansion tank or pressure regulator needed here?

Get the answers in writing, in the contract. Always ask for the contractor's license number and proof of insurance, and check the license with your state or local licensing agency. How to hire a contractor · Quick question? Contractor's Desk ($5)

Warranty

Water heaters and fixtures carry manufacturer warranties (read tank vs parts vs labor terms). Get the plumber's labor warranty in writing.

Expect two kinds of warranty: the manufacturer's product warranty (shingles, windows, fixtures, equipment) and the contractor's workmanship warranty on the installation. Get both in writing with the length, what is covered and how to make a claim. Many product warranties require registration or installation per the manufacturer's instructions. In Arizona, a homeowner can file a workmanship complaint against a licensed contractor with the Registrar of Contractors within two years of the last work performed on a remodel or repair.

DIY vs. hire out

Usually OK to DIY

  • Replacing a faucet aerator, showerhead, toilet flapper or supply line
  • Clearing a simple clog

Hire a licensed pro

  • Water heaters (gas venting, relief valves), repipes, drain lines, gas lines
  • Anything needing a permit

Some work legally requires a licensed contractor and a permit even on your own home. Check your state and city rules.

Permits to expect

Water heaters, repipes, new drain lines and moving fixtures usually require a permit and inspection. Permit rules are set by your city, county and state, so they vary a lot. Call or check the website of your local building department before work starts. When a permit is required, the licensed contractor usually pulls it in their own name.

General information, not legal advice. Requirements vary by location.

Sources

Check a contractor license: search your state's contractor licensing board, or find your state consumer protection office. External sites open in a new tab; Corky's MHS™ is not affiliated with them.

Please note

Educational information only - not legal, engineering or code advice. Rules vary by state, county and city, and change over time. Check with your local building department and licensing board, and read your own contract.