Saturday morning, two cups of coffee in. The list is on the kitchen counter: under each sink, around each toilet, near the water heater, at the laundry connections, the outdoor faucets, the sump pit, the cleanouts. It takes about an hour. Most years nothing notable shows up. The years something does, the catch is usually small enough to fix on a regular service call rather than during an emergency.
A yearly walk-through of a home’s plumbing produces a different result than waiting for problems to announce themselves. Most plumbing failures send small signals before they become large failures, and a homeowner who has done a deliberate inspection in the last twelve months is much more likely to catch those signals than one who hasn’t. The work doesn’t take long, doesn’t require specialized tools, and doesn’t involve any actual repair. The point is observation: noting where things look right, where they don’t, and where a follow-up might be needed.
Repair work, internal flushing, and any task that involves actually fixing what’s found are deliberately outside the scope of a homeowner inspection; those calls go to a plumber.
Visible leaks at predictable points
Visible leaks are the first thing to check, and they show up in predictable places. Open the cabinet under each sink and look at the supply line connections, the drain trap, and the underside of the sink basin for any sign of drips, water staining, or mineral deposits. Around each toilet, look at the supply line where it connects to the tank, the base of the toilet where it meets the floor, and the floor around the toilet itself for moisture or staining. Near the water heater, look at the connections at the top of the tank, the temperature and pressure relief valve discharge pipe, and the floor around the base. Look at hose bibs (the outdoor faucet connections) for drips and at the connection points where outdoor faucets pass through the wall.
Tiny leaks that look insignificant today can warp cabinet bases, breed mold, and produce surprising water bill increases over the course of a year; household leaks add up to thousands of gallons of wasted water annually in many homes that have them.
Shutoff valves: turn each one
Shutoff valves should be tested at least once a year by turning each one through its full range of motion. The main shutoff at the meter or where the supply line enters the house should turn easily. Each fixture’s individual shutoff (under sinks, behind toilets, next to the washing machine) should turn through its full range without resistance. Valves that haven’t been moved in years sometimes seize in their current position from mineral deposits and oxidation, and a seized main shutoff is the difference between a contained leak and a flooded floor when an emergency happens. The act of turning each valve restores its mobility and identifies any that have already failed. A valve that won’t turn or won’t fully close goes on the list for replacement; it doesn’t need to be replaced this week, but it needs to be replaced before it’s needed urgently, ideally as part of a scheduled service call with a vetted plumber rather than during an emergency.
Water pressure: a number on a gauge
Water pressure should be measured with an inexpensive pressure gauge that screws onto a hose bib or laundry connection. The reading typically falls in the 40 to 80 pounds per square inch range for residential systems, with most homes settling somewhere in the middle of that range. A reading well below 40 PSI or well above 80 PSI is information worth acting on; non-leak causes of low pressure and the issues that high pressure creates for the plumbing are covered in a dedicated diagnostic guide. The gauge itself costs little and reads in seconds, and a year-over-year comparison of the same measurement reveals trends that a single reading doesn’t.
Toilets: the food coloring test
Toilets are worth a specific test because they are common quiet leakers. A toilet that’s leaking from the tank into the bowl wastes water continuously without any audible sign. The simplest test is to add a few drops of food coloring to the tank water and wait fifteen or twenty minutes without flushing. If the colored water shows up in the bowl during that time, the flapper or fill valve is leaking and the toilet is using more water than it should. The fix is straightforward but is a repair task rather than an inspection task, so it’s noted for follow-up rather than performed during the walk-through.
Water heater: visual only
The water heater warrants a brief visual inspection, with the operative word being visual. Look at the tank for rust on the outside, water on the floor around the base, mineral staining on the cold and hot water connections at the top, and the discharge pipe for the temperature and pressure relief valve for any signs that the valve has been releasing water. Note the unit’s age (the manufacturer’s serial number on the side of the tank encodes the build date) and compare it to the expected service life for that water heater type. Active flushing of the tank, which removes sediment, is best handled by a plumber rather than as part of a homeowner inspection because of the temperature and pressure of the water involved. End-of-life replacement decisions for the water heater are covered in a separate guide on lifespan and end-of-life signs.
Drains: flow rate at each fixture
Drains should be checked for flow rate at each fixture. A sink that drains noticeably slower than it did six months ago is showing the early stage of a clog that hasn’t reached the point of backing up. Identifying it early lets the homeowner address the cause (drain clog culprits are covered in a dedicated guide) before the slow drain becomes a stoppage. Tubs, showers, and floor drains all benefit from the same observation. Listening for gurgling sounds during drainage is also worth noting; gurgling can indicate a venting issue or a developing clog further down the system.
Sewer cleanouts: locate and confirm
Sewer cleanouts should be located and confirmed accessible. The main cleanout (typically a capped pipe near where the building drain exits the foundation) and any secondary cleanouts at major branch line junctions are the access points used for any drain cleaning service. Knowing where each cleanout is and confirming that the cap can be unscrewed if needed (without actually removing it) saves diagnostic time on a future service call. Cleanout caps that have rusted in place, gotten buried under landscaping, or been finished over with drywall in basement remodels are worth flagging for the next plumbing visit.
Washing machine hoses
Washing machine hoses should be inspected for cracking, bulging, or rust at the fittings. The standard rubber washing machine hose fails over time, and burst washing machine hoses are responsible for a substantial share of residential water damage claims. Replacing rubber hoses with braided stainless steel hoses is a small upgrade that buys real protection, but the inspection itself is just looking for early warning signs of failure on whatever is currently installed. Hose age matters; many manufacturers recommend replacement every five years regardless of visible condition.
Sump pumps
Sump pumps, if the home has one, should be tested by pouring a few gallons of water into the sump pit and confirming that the pump activates, runs through its cycle, and shuts off normally. A sump pump (a basement-floor pump that automatically removes water from a sump pit during heavy rain or rising groundwater) that doesn’t activate is one that won’t be there during the storm that needs it. Battery backups and water-powered backups should be tested according to manufacturer instructions; a sump system without a working backup is one power outage away from being useless when most needed.
Outdoor faucets before freeze
Outdoor faucets and irrigation system shutoffs should be confirmed before the first hard freeze of the year. Hose bibs that aren’t frost-free should be drained, and supply lines feeding outdoor faucets should be shut off and drained as well. Frozen pipe prevention as a freestanding topic is covered in a dedicated before-during-after guide; the inspection-only piece here is verifying that the equipment is in working order and ready for whatever protection plan the climate requires.
What’s not on this list
What this checklist deliberately doesn’t include is repair work. Water heater flushing, drain snaking, valve replacement, hose replacement, fixture rebuilds, and any task that involves actually fixing rather than identifying are not part of the homeowner inspection. The output of an annual walk-through is a list, which becomes the agenda for whatever combination of homeowner repairs and plumber service calls the year requires. The hour spent walking the home produces a punch list, not a punch in.
The point is that inspection and repair are different functions and belong on different days. The output of an inspection is a list of items to track or address; the work of fixing them happens later, on a separate visit or a separate weekend. Keeping those two days separate is what makes the yearly habit sustainable across the years where it actually matters.
