Quick Overview

An annual whole-house plumbing inspection helps you catch small problems before they become expensive repairs. By checking your water supply lines, drains, fixtures, water heater, and outdoor plumbing once a year, you can reduce the risk of leaks, water damage, mold growth, and unexpected plumbing emergencies.

This checklist is designed for homeowners and beginners and can be completed over a few hours.

Download Printable Version – Annual Whole-House Plumbing Inspection Checklist

Before You Start

◻️ Choose a day when you have enough time to inspect the entire property.

◻️ Locate the main water shut-off valve and make sure everyone in the home knows where it is.

◻️ Gather any maintenance records from previous inspections or repairs.

◻️ Make a list of any plumbing problems you have noticed during the past year.

◻️ Check that all utility rooms, crawl spaces, basements, and attics are accessible.

◻️ Make sure you have adequate lighting for dark areas.

◻️ Review the owner’s manuals for your water heater, water softener, and other plumbing equipment if available.

◻️ Keep a notebook or mobile device nearby to record any issues that need future attention.

Tools, Supplies, or Resources Needed

Step-by-Step Checklist

Main Water Supply

◻️ Locate and inspect the main water shut-off valve for corrosion, leaks, or stiffness.

◻️ Turn the valve slightly if recommended by the manufacturer to ensure it operates properly.

◻️ Inspect the main water line entering the home for visible leaks or rust.

◻️ Check the home’s water pressure using a pressure gauge. Ideal residential pressure is generally between 40 and 80 PSI.

Water Heater Inspection

◻️ Look around the base of the water heater for moisture or rust stains.

◻️ Inspect all water connections for slow leaks.

◻️ Check the temperature setting. Around 120°F is recommended for most homes.

◻️ Inspect the temperature and pressure relief valve discharge pipe for proper installation.

◻️ Examine the venting system on gas water heaters for loose or damaged connections.

◻️ Flush sediment from the tank if recommended by the manufacturer.

◻️ Check the expansion tank for signs of waterlogging or corrosion if one is installed.

Indoor Water Supply Pipes

◻️ Inspect exposed pipes under sinks and inside cabinets for leaks.

◻️ Check for corrosion, mineral buildup, or discoloration.

◻️ Look for signs of pipe movement or loose supports.

◻️ Inspect pipes in attics, crawl spaces, and basements for moisture or insulation damage.

◻️ Replace deteriorated pipe insulation where needed.

Faucets and Fixtures

◻️ Turn on every faucet and check for drips or leaks.

◻️ Verify that hot and cold water operate correctly.

◻️ Inspect around faucet bases for signs of water intrusion.

◻️ Clean faucet aerators if water flow appears restricted.

◻️ Check showerheads for leaks or excessive mineral buildup.

Toilets

◻️ Add a few drops of food coloring to each toilet tank and wait 15 minutes to check for silent leaks.

◻️ Inspect the toilet base for water stains or movement.

◻️ Flush every toilet to confirm proper operation.

◻️ Check the shut-off valve and supply line for leaks.

◻️ Ensure the fill valve and flapper are functioning properly.

Sinks, Tubs, and Showers

◻️ Fill and drain each fixture while watching for leaks underneath.

◻️ Inspect caulking around tubs and showers for cracks.

◻️ Check overflow drains for proper operation.

◻️ Verify that drains clear quickly without backing up.

Drains and Waste Lines

◻️ Listen for unusual gurgling sounds that could indicate venting problems.

◻️ Inspect visible drain pipes for leaks or corrosion.

◻️ Check cleanout plugs for accessibility and condition.

◻️ Watch for slow drains that may indicate developing blockages.

Garbage Disposal

◻️ Run cold water and operate the disposal to confirm smooth operation.

◻️ Listen for unusual noises or vibration.

◻️ Inspect the mounting assembly and drain connections for leaks.

◻️ Check the reset button location for future reference.

Dishwasher and Refrigerator Water Lines

◻️ Inspect supply hoses for cracks, bulges, or wear.

◻️ Look for moisture around appliance connections.

◻️ Confirm shut-off valves operate properly.

Washing Machine Plumbing

◻️ Inspect hot and cold supply hoses for deterioration.

◻️ Replace old rubber hoses with braided stainless steel hoses if needed.

◻️ Check the drain hose for secure installation.

◻️ Look for leaks behind and underneath the machine.

Outdoor Plumbing

◻️ Inspect exterior hose bibs for leaks or freeze damage.

◻️ Test outdoor faucets for proper operation.

◻️ Check irrigation systems for broken heads or leaks.

◻️ Inspect exposed outdoor piping for damage.

◻️ Verify yard drains are free of debris.

Sump Pump (If Installed)

◻️ Pour water into the sump pit to verify pump operation.

◻️ Check the discharge pipe for obstructions.

◻️ Inspect the check valve for proper function.

◻️ Confirm battery backup systems are operational if equipped.

Water Softener and Filtration Systems

◻️ Check for leaks around tanks and fittings.

◻️ Verify salt levels if applicable.

◻️ Replace filters according to manufacturer recommendations.

◻️ Inspect drain connections for proper operation.

Check for Hidden Leaks

◻️ Turn off all water fixtures and observe the water meter for movement.

◻️ Compare current water bills to previous months for unusual increases.

◻️ Inspect ceilings, walls, and flooring for water stains.

◻️ Look for mold, mildew, or musty odors.

Common Mistakes to Avoid

Ignoring small drips because they seem harmless.
Forgetting to inspect hidden plumbing areas.
Using chemical drain cleaners as routine maintenance.
Overlooking appliance supply hoses.
Neglecting outdoor plumbing fixtures.
Failing to document problems found during the inspection.
Waiting until a plumbing emergency occurs before calling a professional.

Safety, Quality, or Success Tips

Wear gloves and eye protection when inspecting plumbing equipment.
Never touch electrical components while standing in water.
Keep a record of repairs and maintenance dates.
Replace aging hoses before they fail.
Photograph any damage for insurance or repair purposes.
Address minor issues promptly to prevent costly damage.

Final Review Checklist

◻️ The entire home has been inspected.

◻️ All fixtures have been tested.

◻️ Water supply lines have been checked.

◻️ Drain systems have been evaluated.

◻️ The water heater has been inspected.

◻️ Appliance water connections have been examined.

◻️ Outdoor plumbing has been checked.

◻️ Any leaks or defects have been documented.

◻️ Maintenance records have been updated.

◻️ Repairs requiring professional service have been identified.

When to Get Help

Contact a licensed plumber if you discover:

Water stains with no obvious source.
Active leaks inside walls or ceilings.
Low water pressure throughout the home.
Sewer odors inside the house.
Repeated drain backups.
Water heater leaks or venting problems.
Cracked or severely corroded pipes.
Water meter movement when no water is being used.
Foundation moisture related to plumbing leaks.
Any plumbing issue that you are not comfortable repairing safely.

A professional annual inspection can identify hidden issues that may not be visible during a homeowner inspection and can help extend the life of your entire plumbing system.