Home Plumbing Inspection Checklist

Plumbing problems are among the most expensive issues a home buyer can inherit. A failing sewer line can cost $10,000 or more to replace, a water heater replacement runs $1,000 to $3,000, and hidden leaks can quietly destroy floors, walls, and foundations. The standard home inspection covers basic plumbing checks, but it rarely goes deep enough to catch every problem.

This checklist walks through everything you should examine when viewing a home, from the street connection to the last fixture. Use it to spot red flags early — and to negotiate repairs or credits before you sign the final paperwork.

The pipe material in a home reveals a lot about its plumbing history. Homes built before 1986 may have galvanized steel pipes, which corrode from the inside and restrict water flow. Polybutylene pipes, installed between 1978 and 1995, are notorious for premature failure. Copper and PEX are generally the safest bets — the tradeoffs between the two are covered in our PEX vs copper comparison.

• Look for exposed pipes in the basement, crawl space, or garage
• Check visible joints and fittings for corrosion, dampness, or white mineral deposits
• Run water for a full minute and check the flow and pressure at every tap
• Smell and look at the water — odd colors, metallic taste, or sulfur odor are red flags
• Ask whether the house has a main shutoff valve and where it is located
• Note the condition of the main supply line entering the house

If the home has hard water, mineral buildup can shorten the life of fixtures and appliances. A quick test kit costs a few dollars and is worth running during your visit. Hidden leaks in the walls are harder to spot — learn the professional detection methods in our hidden leak guide.

Your visual walkthrough can only see so much. A licensed plumber can perform a more thorough evaluation, including pressure testing, camera inspections of the sewer line, water heater evaluation, and checks for slab leaks that a general inspector might miss. This is especially important for older homes, homes with finished basements, or any property where you noticed warning signs.

A professional plumbing inspection typically costs a few hundred dollars and delivers a detailed report you can use in negotiations. If issues are found, you can request the seller to fix them, negotiate a lower price, or walk away with confidence. If the house checks out, you gain peace of mind and a maintenance plan for the future. Choosing a qualified professional matters — our guide to choosing the right plumber walks through the vetting process.