Household Plumbing Inspection Checklist

Household Plumbing Inspection Checklist

The Spruce / Paige McLaughlin

When plumbing problems erupt suddenly, they can do so with a severity that borders on the catastrophic. But a regular inspection of your key plumbing fixtures can help you spot and correct developing problems before they become such emergencies.

Predictably, the places where you should focus your inspection checklist are those rooms where there are many plumbing fixtures—the bathroom and kitchen. But don't forget to check around the house for the other appliances and fixtures, ranging from the hose spigots outside the house to the water heater in the basement or utility area.


Bathrooms get lots of use by every member of the family, and it's no surprise that this is the room most likely to see plumbing problems.

  • Faucets. It is the sink, tub, and shower faucets that most often need attention in a bathroom. Check them regularly for leaks. Replace bad washers or cartridges to remedy dripping faucets. Water supply lines hidden in the walls for tub and shower drains can be especially problematic since such hidden leaks can cause major damage before you even spot it. Hidden water pipe leaks often reveal themselves with signs of water damage in the room below the plumbing pipes. Watch the operation of faucets as you run the water—if you notice weak water pressure or an irregular spray pattern, it may be because there is calcium buildup on the aerator. Aerators can be removed and cleaned manually, or calcium buildup can be removed by soaking in vinegar.
  • Drains. Tub, shower, and sink drains in a bathroom are especially prone to soap and hair clogs, and rather than waiting for these to become full blockages, you should periodically clear the drain with boiling water or another homemade method, use a drain blocker, and remove hair and debris from the tub or drain blocker promptly.
  • Toilets. A toilet has many working parts, and any one of them can wear down and cause problems. Remove the tank lid on the toilet and watch what happens as you flush it. A toilet that continues to run rather than shutting off at the end of the flush cycle is wasting a lot of water. Fixing a running toilet is often remarkably easy. If your toilet rocks slightly when you sit on it, or if you notice water seeping around its base, then it is likely that the wax ring that seals the toilet base to the drain opening has worn out and needs to be replaced.
  • Caulk seals. Although the caulk around tubs and showers is not actually "plumbing," when caulking fails, it can allow water from a bathtub or shower to get behind walls and under floors, and the resulting water damage can be catastrophic. Periodically check all caulk beads along floors and walls to make sure it is intact. Seal any gaps you find with fresh caulk. Every few years, it is a good idea to remove the old caulk and apply a new bead of high-quality silicone tub-and-shower caulk.
Toilet handle pushed down to check water flushing

The Spruce / Kevin Norris


The kitchen is another room heavy with plumbing fixtures. At least twice a year, inspect all the fixtures and fix any problems you find.

  • Sink drains. The kitchen sink gets lots of use, and a sink strainer is a common place where leaking can occur. Watch the strainer area and the P-trap as water in the sink drains out. P-trap fittings may need to be tightened, and the strainer basket should be replaced when it begins to leak or becomes corroded. A sink that drains too slowly may have a clog building in the P-trap or branch drain; these fittings can be disassembled and cleaned out. Clean the kitchen sink drain occasionally. Running a mild homemade drain cleaner made of vinegar, baking soda, and water through your kitchen sink drain regularly will help to break up the usual buildup in the drain and keep the water flowing.
  • Faucets. A leaky kitchen faucet is the single most common plumbing repair there is, and it can quietly waste hundreds of gallons of water each year. Watch your faucet carefully as you operate the lever, and repair the faucet if it requires it.
  • Shutoff valves. The fixture shutoff valves that control the water supply to the sink faucet, dishwasher, and refrigerator water lines are intended to completely shut off the flow of water when they are closed. During your inspection, close the valves tightly and make sure they operate as intended. If they do not shut off the water completely, they should be replaced.
  • Garbage disposer. Problems with garbage disposers usually are found in the drain connections where a dishwasher discharge connects to the disposer, or where the disposer discharge runs to the sink drain. Inspect these points and tighten the connections or replace the gaskets if they show signs of leaking. A garbage disposer that has a foul smell should be cleaned. Follow the manufacturer's advice for routine maintenance of the garbage disposal.
  • Dishwasher. During your inspection tour, take a few minutes to watch and listen to the dishwasher in action. A dishwasher that is slow to fill may have a problem with the water supply hose or the shutoff valve that controls it. If the dishwasher is slow to drain, or if drain water remains in the bottom of the dishwasher after the cycle is over, inspect the water discharge hose for clogs or pinching.
  • Refrigerator. A refrigerator with a water dispenser and icemaker should have its filter replaced regularly—most manufacturers recommend twice each year. A clogged filter can block water flow to the dispenser or icemaker. Also, check the water supply hose for signs of wear; replace it if necessary.
Kitchen sink drain installed under kitchen sink

The Spruce / Kevin Norris

Septic and Sewer

A stoppage in the main sewer line or septic system is a very serious plumbing problem and one that poses potential health risks. Regular inspection and maintenance is the best way to prevent this.

  • Maintain the septic system. If you have a septic system with a drain field (common in rural areas) avoid problems by having the system inspected and serviced regularly. With a tank system, have the tank pumped out whenever it becomes full. For drainage field systems, make sure your family knows what kinds of materials should not go down the drain. Many experts suggest that you avoid flushing food materials into a septic system. Bleach-based cleaners should also be avoided since these interfere with the biological breakdown of wastes that is essential to a septic system.
  • Maintain your sewer main. If your house is served by municipal sewer lines, prevent mainline blockages through regular maintenance. For homes that see periodic stoppages, usually caused by tree roots in the sewer lines, an annual snaking of the line by a professional sewer service will prevent floor drains from backing up into the home. You can evaluate the effectiveness of the sewer line by emptying all sinks and tubs at the same time and seeing if a floor drains back up or if it takes a long time for all the drains to empty. Watch for signs of a pending sewer drain clog and deal with them before they become full-blown stoppages.
  • Inspect vent pipes. An integral part of your home's drain and sewer system are the vent pipes that equalize air pressure and vent sewer gases. These pipes usually exit through the top of your roof, and if they become blocked with debris or snow and ice, the drain system in your house will not work as effectively. During your tour of the plumbing system, visually inspect the vent pipes extending through your roof for signs of blockage. You will likely have several of these vent pipes in your roof—one for each main soil stack, and often secondary vent pipes, as well.
Long blue tube going into septic tank below ground

The Spruce / Margot Cavin

Around the House

The bathroom, kitchen, and sewer system are the major plumbing components, but some many other fixtures and appliances should be periodically inspected for problems:

  • Water heater. Look for signs of water leaking in the cold water inlet pipe and hot water exit pipe above the water heater. Also, look around the base of the water heater for leaking that may be caused by a faulty temperature and pressure (T and P) relief valve, or a bad drain valve. Every few years, the water heater tank should be flushed to remove sediment from the bottom of the tank. On gas water heaters, the burner unit should occasionally be inspected and cleaned by a professional service person.
  • Branch shutoff valves. If your system has shutoff valves that control different zones of the plumbing system, check these to make sure they are operating properly. If you find faulty valves, they should be replaced.
  • Sump pump. If your home has a basement with an under-floor drainage system and sump pit, check this to make sure it is operating properly. You can do this by filling the sump pit with water manually and checking to make sure the pump activates to empty the water.
  • Outdoor hose spigots. Outdoor faucets often get overlooked, but these, too, can develop leaks and need repair—by replacing washers or cartridges. Outdoor spigots in cold climates can be especially prone to cracking due to extreme winter temperatures; replace any bad spigots you find.
  • Irrigation system. Lawn sprinkler systems should be inspected at the start of the watering season to make sure all spray heads are operating properly. And at the end of the watering season, the system should be winterized and drained or blown free of water to prevent freezing and rupture of the pipes over the winter.
  • Washing machine. Periodically inspect the water hoses for signs of wear. Rubber hoses that begin to bulge are near the end of their useful lives and should be replaced. Hoses that burst while the owners are away are a major cause of expensive water damage. Also, check the valves that control the hot and cold water hoses for your washing machine. Replace them if they do not completely stop the flow of water when shut off.
  • Check home water pressure. Avoid excess stress on your home's plumbing system by making sure the water pressure is at a safe level. It only takes a few minutes to test water pressure with a pressure gauge. If the pressure is too high, then install or repair/replace the pressure regulator to bring it down to a safe level.
A residential water heater

The Spruce / Candace Madonna