Plumbing inspection checklist: a whole-home plumbing inspection your techs can run in one visit

A plumbing inspection is the visit where you find the failed supply line before it floods the laundry room. It is also the visit where a homeowner decides whether to trust your recommendations. Both depend on the tech checking the same things in the same order, and writing down what they found.

This checklist is for a whole-home plumbing inspection on a typical single-family house: a maintenance plan visit, a new-homeowner check, or a paid inspection before a remodel. It is not a code inspection and not a pre-purchase home inspection, which follow their own standards (see the home inspection scheduling page for that trade).

Before you start

1. Confirm the homeowner's concerns: leaks, slow drains, low pressure, noisy pipes, water quality, high water bills.
2. Ask the age of the house and of the water heater, and whether the home is on city water or a well, and sewer or septic.
3. If you smell gas at any point, stop. Follow the Pennsylvania PUC's gas emergency steps or your own utility's: leave the building, avoid sparks, and call 911 and the gas utility from a safe distance.
4. Photograph each area as found.

The checklist

Water supply and pressure

1. Main shutoff: locate it, label it, confirm it turns. Show the homeowner where it is.
2. Static water pressure: attach a gauge to a hose bibb or the laundry cold tap and record it. EPA WaterSense notes that most U.S. plumbing codes require a pressure-regulating valve where supply pressure exceeds 80 psi, and recommends service pressure between 45 and 60 psi.
3. Pressure-reducing valve, if present: record its setting and whether the gauge reading matches.
4. Thermal expansion: if there is a PRV or check valve, look for an expansion tank or other control as your local code requires, and check the tank's charge if one is there.
5. Water meter: with all fixtures off, watch the leak indicator for a minute or two. Movement suggests a hidden leak.
6. Service pipe material where it enters the house. The EPA says lead pipes are more likely in older cities and homes built before 1986. If the pipe looks like lead, tell the homeowner and point them to their water utility.
7. Visible supply piping: material, corrosion, green or white crust at fittings, signs of past repairs.
8. Well systems: pressure tank, pressure switch, gauge reading.

Water heater

9. Type, fuel, capacity and age from the data plate.
10. Temperature setting. The DOE Energy Saver guide suggests 120°F, which it calls safe for most of the population.
11. Temperature and pressure relief valve: present, discharge pipe the right material, size and termination per local code. Test only as the manufacturer directs, and warn the homeowner first.
12. Signs of leaks, rust at the base, or water in the pan.
13. Sediment: the same DOE guide suggests draining a quart every three months, following the manufacturer's directions. Ask when it was last done.
14. Anode rod: inspect if the manufacturer and your time allow.
15. Gas units: venting connected and sloped, no scorching at the burner door, gas shutoff present, sediment trap present.
16. Electric units: no signs of overheating at the junction box.
17. Tankless units: descaling history, isolation valves, error codes.

Fixtures, room by room

18. Each faucet: drips, leaks under the sink, hot and cold on the correct sides.
19. Each fixture shutoff valve: present, turns, does not leak when operated.
20. Supply lines: material and condition. Braided lines bulging, kinked or corroded at the crimp go on the recommendation list.
21. Each toilet: runs or ghost-fills, rocks on the floor, leaks at the base or the tank bolts.
22. Showers and tubs: valve operation, drain speed, caulk and grout at the fixture.
23. Washing machine: hose condition and age, shutoff accessible.
24. Dishwasher and refrigerator lines: no leaks at connections.
25. Hose bibbs: no drips, frost-proof where your climate needs it, backflow device where code requires it.

Drains, waste and vent

26. Each drain: fill and release, time how fast it clears.
27. Traps under sinks: no leaks, no improvised fittings.
28. Cleanouts: located and accessible.
29. Sewer or septic: any gurgling, backups or odors reported. Recommend a camera inspection if there are signs of a main line problem.
30. Sump pump, if present: test that it starts and discharges away from the house.
31. Vent issues: slow drains on several fixtures or sewer odor can point at venting.

Gas piping (if your license covers it)

32. Appliance shutoffs present at each gas appliance.
33. Flexible connectors in good condition.

Close-out

34. Restore everything you shut off and check for leaks at each valve you operated.
35. Record every reading on the work order: pressure, water heater temperature, ages, drain times.
36. Write findings in three tiers: safety (fix now), soon (likely to fail), monitor (watch at the next visit).
37. Price each recommendation clearly before you leave. The quoting and estimates guide covers how to present options.
38. Leave the homeowner a copy with the main shutoff location written at the top.

Why the order matters

Pressure comes first because it can explain other findings. The same EPA sheet notes that high pressure can damage piping, fixtures and appliances and raise the risk of leaks. If pressure is the cause of a running toilet and a dripping faucet, fixing pressure first may make some "repairs" unnecessary, and recommending them separately would erode trust.

The meter test comes before the fixture walk because a moving leak indicator tells you to look harder in the rooms that follow.

Findings are tiered because a homeowner handed fifteen recommendations with no order may do none of them. Three tiers make the decision easy.

How to adapt it

• Add your region. Freeze-prone areas add pipe insulation and frost-proof bibbs. Hard-water areas add scale checks and softener or filter systems.
• Time-box it. Decide how long the inspection should take for a typical house in your area and book it at that length. Measure the real time on site over a month and adjust.
• Keep it in the service history. Next year's inspection compares against this year's readings, which is what makes a preventive maintenance plan worth paying for. The plumbing scheduling page covers how to fit these visits around emergency calls.

Common questions

What is included in a home plumbing inspection?

A whole-home plumbing inspection usually covers the main shutoff, water pressure, a meter leak test, the water heater, every faucet, toilet and shower, supply lines and shutoff valves, drains and traps, cleanouts, sump pump and, where relevant, gas appliance shutoffs. The tech records readings and gives the homeowner tiered recommendations.

What water pressure is too high for a house?

EPA WaterSense notes that most U.S. plumbing codes require a pressure-regulating valve where supply pressure exceeds 80 psi, and it recommends 45 to 60 psi at the service. Your local code decides the rule where you work, so check it.

How often should a home plumbing system be inspected?

A yearly inspection is a common rhythm for maintenance plans. Older homes, homes with past leaks and homes on wells or septic systems may warrant checking more often. Agree a frequency with the homeowner based on what you find.

How long does a plumbing inspection take?

It depends on the size of the house and the number of fixtures. Book a standard length for a typical house in your area, record the actual time on site for a month of inspections, and adjust the booking length to match.