What Does a Plumber Do? A Complete Guide

Most people call a plumber only when something goes wrong — a burst pipe, a backed-up drain, a water heater failure. But licensed plumbers do far more than emergency repairs. Understanding the full scope of plumbing work helps homeowners make better decisions about maintenance, renovation planning, and when to call a professional vs. attempt DIY.

What Plumbers Are Licensed to Do

A licensed plumber is trained and legally authorized to:

• Install, repair, and replace water supply lines (cold and hot)
• Install, repair, and replace drain, waste, and vent (DWV) systems
• Install and service water heaters (gas, electric, tankless)
• Connect gas lines for plumbing appliances in most states
• Install and repair fixtures (faucets, toilets, sinks, showers, tubs)
• Repair and replace sewer lines
• Install plumbing for renovations and new construction
• Pull permits for plumbing work and coordinate with building inspections
• Perform leak detection and pipe testing
• Install backflow prevention devices
• Install water treatment and filtration systems

The Difference Between Journeyman and Master Plumber

Plumber licensing has tiers:

• Apprentice: Learning on the job under a licensed plumber, typically in a 4–5 year apprenticeship program combining classroom instruction and field experience.
• Journeyman Plumber: Has completed apprenticeship and passed a licensing exam. Can work independently. State licensing requirements vary.
• Master Plumber: Has additional experience (typically 2–4 years as journeyman) and has passed a more comprehensive exam. Can own a plumbing business, pull permits, and supervise apprentices and journeymen.

When you hire through Plumbing Crew USA, you are connected with licensed plumbers who have met their state's requirements for independent operation.

What Plumbers Do NOT Do

Plumbers are not HVAC technicians (heating, ventilation, and air conditioning) — though some work in both trades. Plumbers do not typically:

• Service or repair forced-air heating systems or central air conditioning
• Handle electrical wiring beyond what's directly associated with plumbing appliances
• Perform appliance repair on washing machines or dishwashers beyond the water connections
• Perform roofing work, even when related to pipe flashings and penetrations

Emergency vs. Non-Emergency Plumbing

Plumbing emergencies requiring immediate professional response:

• Burst or actively leaking pipes with water damage occurring
• Complete sewer backup into the home
• Gas line leak (leave the home immediately and call the gas company first)
• No water service to the home
• Overflowing toilet that cannot be controlled by the supply valve
• Water heater leaking with flooding

Non-emergency situations that can be scheduled:

• Slow drains
• Dripping faucets
• Running toilets
• Planned fixture replacement
• Water heater approaching end of life
• Annual plumbing maintenance inspection

Should You Attempt DIY Plumbing?

Some plumbing tasks are genuinely DIY-friendly:

• Replacing a toilet flapper or fill valve (no special tools, low risk)
• Clearing a simple hair clog with a drain snake
• Replacing a faucet aerator or showerhead
• Fixing a running toilet

Many tasks should be left to licensed professionals, however:

• Any work that requires a permit (new pipe installation, moving drain lines)
• Water heater installation (gas connections, venting, electrical)
• Sewer line repair or replacement
• Any repair inside walls or under slabs
• Pipe replacement or repiping

Unpermitted plumbing work that is discovered during a home sale can derail closing, require expensive remediation, or void insurance coverage. When in doubt, call a professional. Plumbing Crew USA makes it easy — call (888) 766-7573 for a Available 24/7.