What Does a Plumber Do? Services, Costs, and When to Call One

A plain-English guide to what plumbers actually do, typical service costs, how to hire a good one, and when to DIY versus call a pro.

More Than Fixing Leaks

When most people picture a plumber, they imagine someone unclogging a drain or tightening a faucet. That is part of the job, but a professional plumber’s actual scope is much wider. Plumbers install, maintain, and repair the systems that carry water into your home and carry waste water out. That includes supply lines, drain pipes, sewer connections, water heaters, gas lines, fixtures like toilets and faucets, and in many cases the pumps and valves that keep all of it running safely.

In a typical day, a residential plumber might snake a clogged kitchen drain in the morning, replace a water heater at noon, rough in the plumbing for a bathroom remodel in the afternoon, and answer an emergency call about a burst pipe after hours. Commercial plumbers work on bigger systems — restaurants, office buildings, apartment complexes — where the pipe runs are longer, the codes are stricter, and a shutdown costs real money.

Services a Plumber Actually Provides

Drain cleaning and clog removal

This is the bread-and-butter service. Kitchen sinks clogged with grease, bathroom drains full of hair, toilets blocked by too much paper, and main sewer lines invaded by tree roots. For simple clogs, a plumber uses a hand auger or a motorized drain snake. For tougher blockages, they may use hydro-jetting — a high-pressure water jet that scours the inside of the pipe. If the line is damaged, a camera inspection can show exactly where the break or collapse is without digging up your yard first.

Water heater installation and repair

Plumbers handle both tank and tankless water heaters. A standard tank heater repair — replacing a heating element, thermostat, or pressure-relief valve — is routine work. Full replacement is also standard: disconnect the old unit, haul it away, set the new one, connect water, gas or electric, and venting. Tankless units cost more to install but last longer and take up less space. Most plumbers will tell you a conventional tank heater lasts around 8–12 years, after which replacement makes more sense than another repair.

Fixture installation and repair

Toilets, faucets, sinks, shower valves, garbage disposals, sump pumps, and hose bibs all fall here. Replacing a toilet or faucet is straightforward for a pro and often takes under two hours. Shower valve problems — water that won’t get hot, a handle that won’t turn — usually mean a cartridge replacement, which is quick if the valve is accessible.

Pipe repair and repiping

Pipes corrode, freeze, and burst. A plumber repairs broken sections and, for older homes with galvanized steel or polybutylene pipe, may recommend a full repipe with copper or PEX. Repiping a whole house is a multi-day job, but it eliminates the recurring-leak cycle that old pipe systems fall into.

Gas line work

In many areas, licensed plumbers are also certified to install and repair gas lines — for stoves, dryers, fireplaces, and outdoor grills. This is one area where DIY is never appropriate. A gas leak is genuinely dangerous, and most local codes require a licensed professional and a pressure test before the line is put into service.

Sewer line repair and replacement

The line from your house to the street is your responsibility, not the city’s. When it cracks or collapses, plumbers dig it up and replace it (traditional excavation) or pull a new pipe through the old one (trenchless methods like pipe bursting or lining). Trenchless costs more per foot but saves your driveway and landscaping.

Emergency services

Burst pipes, sewage backups, and major leaks don’t wait for business hours. Most plumbing companies offer 24/7 emergency service with a higher rate for after-hours calls.

Typical Costs: What Plumbers Charge in the US

Plumbing pricing varies a lot by region, but these ranges reflect what most homeowners encounter:

  • Service call / trip fee: typically $50–$100, often waived if you hire them for the work. Many plumbers also charge a minimum of one hour.
  • Hourly rate: typically $75–$150 per hour for a licensed plumber, more in high-cost metro areas. Apprentices bill less.
  • Flat-rate jobs (many companies now price common jobs by the task rather than the hour):
  • Drain snaking (simple clog): typically $100–$275
  • Hydro-jetting a main line: typically $350–$600
  • Toilet replacement (labor, you supply the toilet): typically $150–$350
  • Faucet replacement (labor): typically $150–$300
  • Garbage disposal replacement: typically $200–$400 including the unit
  • Water heater repair: typically $150–$500 depending on the part
  • Tank water heater replacement (installed): typically $1,200–$2,500; tankless typically $2,500–$5,000
  • Sewer line replacement: typically $3,000–$10,000+, depending on length, depth, and method
  • Whole-house repipe: typically $4,000–$15,000 depending on home size and pipe material
  • Emergency / after-hours surcharge: often 1.5–2× the standard rate, or a flat emergency fee of $100–$300 on top of the work.

Always get the price in writing before work starts. Reputable plumbers give a clear quote or a clear explanation of how they’ll bill (flat rate vs. hourly) and what could change it.

When to DIY vs. Call a Plumber

Fine to DIY: plunging a toilet or sink, replacing a flapper or fill valve in a toilet tank, swapping a faucet aerator or showerhead, resetting a garbage disposal with the reset button, replacing a visible P-trap under a sink, and using a hand auger on a minor hair clog.

Call a plumber: anything involving the main sewer line, a water heater (especially gas), gas lines of any kind, leaks inside walls or ceilings, no hot water with no obvious cause, low water pressure throughout the whole house, burst or frozen pipes, a sump pump that isn’t working during rain, and any job that requires cutting into walls or soldering pipe if you don’t have the tools and experience. A good rule of thumb: if a mistake would flood your house, poison your air, or violate code, hire the pro.

How to Choose a Good Plumber

  1. Verify the license. Most states license plumbers, and many require the license number on their truck, website, and invoices. You can usually check it on your state’s contractor licensing board website. A licensed plumber has passed exams and carries required insurance — an unlicensed handyman offering plumbing work at half price is a gamble.
  2. Check insurance. A reputable plumber carries general liability insurance and workers’ compensation. If a worker gets hurt on your property or floods your basement, you want that covered.
  3. Read recent reviews, but read them critically. Look for patterns across Google, Yelp, and the Better Business Bureau rather than one angry outlier. Pay attention to how the company responds to complaints.
  4. Get at least two or three quotes for any job over a few hundred dollars. Quotes that are wildly lower than the others often mean corners are being cut — or that extras will appear later.
  5. Ask about the warranty. Good plumbers guarantee their labor, typically for 30 days to a year, separate from the manufacturer’s warranty on parts.
  6. Ask who will actually do the work. Some companies send a salesperson to quote and a different crew to work. That’s fine, but know who is coming and whether they’re licensed or supervised apprentices.
  7. Prefer flat-rate pricing for common jobs. It removes the incentive to work slowly and removes the surprise from your bill.

Red Flags to Avoid

  • No license or unwillingness to provide a license number. Walk away.
  • Demanding full payment up front. A deposit of 30–50% on large jobs is normal; 100% before work starts is not.
  • Vague pricing or refusal to put the quote in writing. “We’ll see when we get in there” is fine as a possibility, not as the whole estimate.
  • High-pressure tactics — “this price is only good today,” or insisting a full repipe is urgent based on a glance.
  • Showing up in an unmarked vehicle with no business name, especially for emergency calls you found through a paid ad.
  • Recommending replacement when repair is reasonable without explaining why. A second opinion is cheap insurance on any quote over $1,000.

What a Plumber’s Day Actually Looks Like

To give you a feel for the trade: a residential service plumber starts the day with a route of 3–6 calls — a mix of scheduled maintenance, quoted repairs, and diagnostics. Each stop involves talking to the homeowner, diagnosing the problem (often with a camera or pressure gauge), explaining options and prices, doing the work, testing it, and cleaning up. Emergency plumbers work on-call rotations for nights and weekends. Apprentices spend their first years assisting licensed plumbers, learning code, and gradually taking on harder tasks; reaching journeyman and then master status takes years of combined classroom and field training. It’s skilled, physical work that combines problem-solving with customer service — the plumber is often in someone’s home on one of their worst days.

FAQ

How much does a plumber cost per hour?
Typically $75–$150 per hour for a licensed plumber in most US markets, plus a service call fee. Rates run higher in expensive metro areas and for after-hours emergencies.

Should I choose flat-rate or hourly pricing?
For common, well-defined jobs (clogged drain, toilet replacement), flat-rate pricing is usually better — you know the cost up front. For exploratory work where the scope is genuinely unknown, hourly with a clear estimate range is normal.

Do I need a plumber for a water heater, or can a handyman do it?
Use a licensed plumber, especially for gas heaters. Water heater installation involves gas or 240-volt electric connections, venting, pressure-relief safety devices, and local code requirements. An improper install can be dangerous and may void your home insurance coverage.

How often should I have my plumbing inspected?
A basic check every couple of years is reasonable for most homes: water heater flush annually, a look at exposed pipes for corrosion, and testing shut-off valves. If your home is over 30 years old or you have large trees near your sewer line, a camera inspection every few years is cheap peace of mind.

What should I do first if a pipe bursts?
Shut off the main water valve to your house immediately — know where it is before you need it. Then turn off the water heater (to avoid damage from running dry), open faucets to drain remaining pressure, and call a plumber. Move valuables away from the water and start mopping while you wait.