Ten Plumbing Problems You Should Never Try to Fix Yourself

DIY plumbing repairs save hundreds of dollars on service calls, but some problems require licensed professionals with specialized tools, expertise, and insurance. Attempting these ten repairs yourself risks catastrophic flooding, gas leaks, code violations, or injuries that cost far more than professional service.

Know when to grab tools and when to grab the phone.

Gas Line Work

Any project involving gas lines requires licensed professionals. Gas leaks kill through explosion or carbon monoxide poisoning. Even small leaks accumulate undetected, then ignite from pilot lights or electrical sparks.

Why Professionals Only

Gas line work requires specific permits in every jurisdiction. Inspectors must verify proper installation before gas service activates.

Licensed plumbers carry liability insurance covering gas-related damage. Homeowner insurance typically denies claims for DIY gas work.

Gas connections use specific materials, thread compounds, and torque specifications. Incorrect installation creates leak points that may not surface immediately.

Pressure testing requires specialized equipment homeowners don't have. Professionals use manometers and detection equipment to verify every joint is leak-free.

Common Gas Line Projects

Installing gas lines for new appliances: ranges, dryers, water heaters, fireplaces

Extending existing gas lines to new locations

Repairing damaged gas lines from renovation or landscaping accidents

Converting appliances between natural gas and propane

Moving gas meters or main shutoff valves

Cost Expectations

Simple gas line extensions cost $300-$800. Complex installations involving multiple appliances or long runs cost $1,000-$3,000.

The peace of mind knowing gas connections won't leak or explode is worth every dollar.

Main Sewer Line Repairs

Main sewer lines run from your house to the street, typically buried 3-6 feet underground. These pipes handle all wastewater from your home. Repairs require excavation equipment, video inspection tools, and knowledge of proper pipe pitch.

Warning Signs

Multiple drains backing up simultaneously indicates main line blockage

Sewage backing up through floor drains or lowest fixtures

Wet spots or sewage odors in your yard above the sewer line

Gurgling sounds from multiple drains when using water anywhere in the house

Why Professional Help is Essential

Video camera inspection identifies exact problem location and cause. Digging without knowing the precise issue wastes time and money.

Excavation requires calling 811 for utility locates. Hitting electric, gas, or water lines during digging creates life-threatening situations.

Sewer lines must maintain proper slope (typically 1/4 inch per foot) for gravity drainage. Incorrect pitch causes ongoing problems.

Many jurisdictions require permits for sewer line work and inspection of completed repairs.

Modern trenchless repair methods (pipe bursting, pipe lining) require specialized equipment and training.

Repair Costs

Video inspection and basic cleaning: $300-$600

Partial sewer line replacement: $1,500-$5,000

Complete sewer line replacement: $3,000-$15,000 depending on length and site conditions

Trenchless pipe lining: $4,000-$12,000

These costs reflect reality. DIY attempts often make problems worse, requiring even more expensive fixes.

Repiping Projects

Whole-house or multi-room repiping involves replacing water supply lines throughout your home. This work requires running new pipes through walls, proper support, correct fittings, and pressure testing.

Scope of Repiping

Old galvanized steel pipes showing severe corrosion

Homes with repeated pinhole leaks in copper piping

Polybutylene pipe replacement (PB pipe failed catastrophically in thousands of homes)

Converting from one pipe material to another

Professional Requirements

Access to walls and ceilings requires cutting and patching drywall. Most plumbers coordinate with drywall contractors.

New pipes must match code requirements for pipe size, material, and support spacing.

Pressure testing verifies all connections before covering pipes with drywall.

Proper slope on drain lines prevents standing water and clogs.

Most jurisdictions require permits and inspections for repiping work.

Costs

Partial repiping (single bathroom): $1,500-$3,000

Multi-room repiping: $3,000-$7,000

Whole-house repiping: $4,000-$15,000 depending on home size and pipe material

Professional repiping comes with warranties covering leaks and defects. DIY pipe work has no warranty beyond your own willingness to rip open walls again.

Water Heater Installation

Water heater replacement might seem simple, but gas and electric units have specific installation requirements that affect safety and code compliance.

Gas Water Heater Hazards

Gas connections require proper thread compound, specific torque, and leak testing

Venting exhaust gases requires knowledge of draft requirements and clearances

Improper venting causes carbon monoxide buildup that kills

Temperature and pressure relief valve installation affects explosion risk

Electric Water Heater Hazards

Electric water heaters typically require 240-volt circuits with specific wire gauge

Incorrect wiring causes fires or electrocution

Proper grounding prevents shock hazards

Code Requirements

Earthquake straps in seismic zones

Specific clearances from combustible materials

Drain pan requirements for units above living spaces

Expansion tanks for closed water systems

Proper support and securing

Costs

Professional water heater installation: $800-$2,500 depending on type and complexity

DIY installation: $400-$600 for the unit plus risk of code violations, voided warranties, and safety hazards

Most water heater manufacturers void warranties if installation doesn't meet their specifications or local codes.

Major Drain Line Work

Replacing or reconfiguring drain lines inside walls requires understanding venting requirements, proper pipe pitch, and how drainage systems function.

Why Drains Are Complex

Every drain fixture requires proper venting to prevent siphoning water from drain traps

Vent pipes must terminate above the roof with specific clearances

Drain pipes need precise slope: too flat causes clogs, too steep leaves solids behind

Improper venting causes gurgling, slow drains, and sewer gas entry

Projects Requiring Professionals

Moving toilets to new locations

Adding bathrooms requiring new drain and vent lines

Replacing cast iron drain stacks

Reconfiguring kitchen drains for island sinks

Any work requiring cutting into main drain stacks

Costs

Adding a bathroom drain system: $1,500-$3,500

Replacing a section of drain stack: $1,000-$3,000

Reconfiguring drains for remodeling: $800-$2,500

DIY drain work that fails code inspection requires ripping out your work and paying professionals to fix it properly. Just hire licensed plumbers from the start.

Foundation or Slab Leak Repairs

Leaks in pipes running beneath concrete slabs require specialized detection equipment and repair methods.

Detection Requirements

Electronic leak detection pinpoints leak location without unnecessary concrete demolition

Pressure testing isolates which pipes are leaking

Thermal imaging can sometimes identify slab leaks through temperature differences

Repair Methods

Breaking through concrete to access and repair pipes

Rerouting lines to bypass leaking sections without demolition

Epoxy pipe lining to seal leaks without pipe replacement

Each method requires expertise homeowners don't have.

Costs

Slab leak detection: $200-$500

Slab leak repair with concrete access: $1,500-$4,000

Pipe rerouting to avoid slab: $1,000-$3,000

Epoxy lining: $2,000-$6,000

Foundation damage from ignored slab leaks costs $10,000-$50,000 to repair. Professional slab leak service prevents this escalation.

Septic System Work

Septic systems involve tanks, distribution boxes, and drain fields that require specific knowledge and equipment.

Professional Requirements

Septic tank location and excavation

Pump-out services before repairs

Drain field replacement or repair

Distribution box adjustment

Septic inspections for home sales

Why Homeowners Shouldn't DIY

Septic tanks contain toxic gases that kill. Hydrogen sulfide and methane displace oxygen, causing death within minutes.

Improper repairs cause system failure requiring $10,000-$30,000 drain field replacement.

Most jurisdictions require licensed septic contractors and permits for any septic work.

Costs

Septic pumping: $300-$600

Septic repairs: $1,000-$5,000

Drain field replacement: $10,000-$30,000

Never attempt septic work yourself. The risks far exceed any potential savings.

Backflow Preventer Installation

Backflow preventers protect drinking water from contamination. Installation requires specific knowledge of plumbing codes and testing procedures.

Code Requirements

Specific backflow preventer types for different hazard levels

Proper installation orientation and clearances

Annual testing by certified testers

Registration with local water utilities

Professional Needs

Licensed plumbers understand which backflow preventers meet code for specific applications

Proper installation prevents device failure

Documentation required for inspections and water department records

Costs

Backflow preventer installation: $300-$1,200 depending on size and type

Annual testing: $75-$150

Improper backflow preventer installation can contaminate drinking water supplies, creating health department violations and liability.

Permit-Required Work

Any plumbing work requiring permits typically needs professional involvement. Permits exist for safety, and inspectors verify work meets code.

Common Permit Requirements

Bathroom additions or relocations

Kitchen remodeling affecting plumbing

Water heater replacement (in many jurisdictions)

Sewer line repairs or replacement

Gas line work

Adding hose bibs to irrigation systems

Why Permits Matter

Code compliance ensures safety

Unpermitted work discovered during home sales forces expensive corrections

Insurance claims may be denied for damage from unpermitted work

Inspectors catch mistakes before they cause problems

Working with Professionals

Licensed plumbers pull permits as part of their service

They schedule inspections and coordinate with inspectors

Their work comes with warranties covering defects

You gain peace of mind knowing work meets code

High-Water-Pressure Problems

Homes with water pressure exceeding 80 PSI need pressure regulators installed on the main water line. This requires shutting off water to the entire house and working on the main supply.

Risks of High Pressure

Pipes and fixtures develop leaks from excessive stress

Water heaters fail prematurely

Appliance valves and supply lines burst

Toilets run constantly from pressure-compromised fill valves

Professional Installation

Pressure regulators install on the main line after the shutoff valve

Installation requires completely draining the system

Proper sizing ensures adequate flow for household needs

Testing verifies correct pressure reduction

Costs

Pressure regulator installation: $250-$600

The investment prevents thousands in damage from high-pressure failures.

When DIY Makes Sense

Not all plumbing requires professionals. Homeowners can successfully handle:

Faucet repairs and replacements

Toilet repairs (flappers, fill valves, handle assemblies)

Supply line replacement under sinks

Aerator cleaning and replacement

Showerhead installation

Simple drain cleaning with augers

Garbage disposal replacement

Shut-off valve replacement

These projects have limited scope, don't require permits, and use standard parts available at hardware stores. Mistakes are containable and fixable without catastrophic consequences.

Questions to Ask Before DIY

Does this project require a permit? If yes, strongly consider hiring professionals.

Could failure cause major water damage? If yes, professional installation protects your home.

Do I have all necessary tools and materials? Specialized tools often cost more than professional service.

Am I comfortable with potential complications? Frozen pipes, stripped fittings, and unexpected problems are common.

Does this work affect gas or electrical systems? If yes, hire licensed professionals.

Will I void warranties or create insurance issues? Many appliances require professional installation to maintain coverage.

Finding Qualified Plumbers

Get three quotes for major projects

Verify licensing and insurance

Check references and online reviews

Ask about warranties on parts and labor

Confirm they'll pull required permits

Get written estimates before work begins

The Bottom Line

Professional plumbers charge $100-$200 per hour plus materials, making simple service calls expensive. But attempting repairs beyond your skill level risks catastrophic failure.

Save DIY efforts for accessible, reversible, low-risk projects. Call licensed plumbers for gas lines, sewer mains, major installations, permit work, and anything you're not completely confident handling.

The money spent on professional service buys expertise, specialized tools, code compliance, warranties, and insurance protection. These benefits far exceed the service cost when projects go wrong.

Know your limits. Replacing a toilet flapper saves $150. Attempting a slab leak repair yourself can destroy your home's foundation. Choose wisely.