Plumbing Inspection Before Buying a House: What It Checks and Why
By Mike Holt, NJ Master Plumber · May 10, 2024 · 3 min read · Updated November 1, 2026
Quick answer
A plumbing inspection before you buy a house is a licensed plumber's check of the water heater, supply and drain pipes, shutoff valves, water pressure and every fixture. It goes deeper than a standard home inspection, which only skims the plumbing and usually skips the sewer line. Book it during your inspection period, and add a sewer camera for older homes or houses with big trees.
Want us to take a look? We find the cause and give you written upfront flat-rate pricing options before any work starts.
A house can look perfect at the showing and still have a sewer line full of roots or pipes rusting from the inside. A plumbing inspection during your inspection period finds those problems while you can still negotiate.
What does a pre-purchase plumbing inspection check?
| What we check | What we're looking for |
|---|---|
| Water heater | Age, leaks, rust at the base, the relief valve and its pipe, venting |
| Supply pipes | Material (copper, PEX, galvanized steel, sometimes lead), corrosion, leaks |
| Main shutoff and fixture valves | Whether they turn and actually stop the water |
| Water pressure | Too low (often old pipes) or too high (can damage fixtures) |
| Drains and vents | Slow drains, gurgling, cracked cast iron, bad slopes, sewer smells |
| Every fixture | Toilets, faucets, tubs and showers for leaks, flow and worn parts |
| Sump pump | Whether it runs, has a check valve and discharges away from the house |
| Signs of past leaks | Stains, soft floors, patched pipes and old repairs |
You get a plain list of what we found and what it means, so you know what's urgent and what can wait.
Is a home inspection enough?
A home inspector covers the roof, electrical, structure, heating and more in one visit. The plumbing gets a visual check of what's exposed. That's useful, but it usually leaves out:
- the sewer line from the house to the street,
- pipes hidden in walls and floors,
- whether the pipe material is near the end of its life,
- how well the valves actually work.
If the home inspector flags anything plumbing related, that's the time to bring in a plumber before your inspection period ends.
When should you add a sewer camera?
For many older Central New Jersey homes, the sewer line is the most expensive plumbing surprise a buyer can get. Add a camera inspection if the house is older, has big trees near the line, or has slow drains in the basement. Our guide to sewer camera inspections explains what the camera finds and what the fixes look like.
What problems do we find most in older NJ homes?
- Galvanized steel supply pipes causing low pressure and rusty water. See signs you need repiping.
- Old cast iron or clay sewer lines with roots or cracks.
- Water heaters past their expected life.
- Shutoff valves that won't close.
- Past DIY work: wrong fittings, missing traps, unvented drains.
What happens after the inspection?
You get our findings in plain language and, where something needs fixing, written upfront flat-rate pricing options for the repair. Your attorney or agent can use that to ask the seller for repairs or a credit. Once you move in, our new homeowner plumbing checklist covers what to learn and check in your first week.
Plumbing Doctor does plumbing inspections for buyers, sellers and homeowners across Central New Jersey. Contact us to confirm whether your job site is within our current service area. The $49 service fee applies, and you get a detailed line-item estimate. A separate report fee may be charged if you tell us that estimate isn't enough for you. Call 908-873-6686 to book an inspection before your deadline.
Get tips and reminders
New guides and seasonal reminders. A few emails a year.
Stop and call us if
- The house is more than about 40 years old.
- The home inspector noted galvanized pipes, low pressure, active leaks or an old water heater.
- There are big trees between the house and the street.
- You see water stains on basement walls, ceilings or under sinks.
Call 908-873-6686.
Michael Holt
Owner and operator of Plumbing Doctor, NJ Master Plumber (Lic. #36BI01345600) and U.S. Marine Corps veteran.
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