A home plumbing inspection checklist helps you look past fresh paint and new fixtures to the systems that are expensive to fix after closing. The part buyers miss most often is the underground sewer line. In Jacksonville, you also need to know when the house was built, what the pipes are made of, and whether your insurer will want a 4-point inspection. Use this list alongside your general home inspection, not instead of it.
What should a plumbing inspection cover before you buy a house?
A plumbing inspection before you buy should answer five questions: what the supply pipes are made of, what the drain and sewer pipes are made of and what shape they’re in, how old the water heater is, whether there’s a hidden leak, and whether the home is on sewer or septic. A general home inspector will usually run fixtures, look under sinks, and note visible leaks or corrosion, which is valuable. But much of the plumbing is out of sight, inside walls, under the slab, and buried in the yard.
I start with the age of the house, because different eras used different materials. Then I identify the visible water piping, drainage, water heater, fixtures, and equipment, and put the whole system together. Check the main shutoff valve and each fixture shutoff, too, since a valve that won’t close is a small repair now and a big problem during a leak.
Here’s the checklist in one place. Pull it up on your phone or print it for the showing:
- Supply pipes: gray plastic marked PB2110 with crimp rings (polybutylene), galvanized steel, copper, CPVC, or PEX. Polybutylene affects insurability.
- Drain and sewer pipes: cast iron, clay, or PVC, plus a camera scope of the main line. InterNACHI lists below-ground cast iron waste pipe at 50 to 60 years.
- Remodels and partial repipes: check pipe in more than one spot, since one new section doesn’t tell you what’s behind every wall.
- Water heater: manufacture date in the serial number, rust, leaks, the drain pan, and the relief-valve discharge pipe. DOE estimates tank units average about 15 years; in Jacksonville I typically see roughly 8 to 12.
- Hidden leaks: water meter moving with everything off. EPA WaterSense says 9% of homes have leaks wasting 50+ gallons a day.
- Sewer or septic: connection type, plus pumping and inspection records. The EPA says septic systems should be inspected at least every three years.
- Shutoff valves: the main and fixture valves close fully.
- Insurance: whether a 4-point inspection is required. Citizens requires one on applications for homes more than 20 years old.
How do you identify pipe material by the home’s age?
The age of the house is your best first clue to what’s in the walls, but only a look at the pipe confirms it. In older homes, I look for cast iron drainage and galvanized steel water piping, the dull gray pipe with threaded joints that tends to rust and narrow over time. For homes built from the late 1970s through the early to mid-1990s, polybutylene is the red flag. It’s usually gray, sometimes marked “PB2110,” and often joined with metal crimp rings at the fittings.
Research published in Polymer Degradation and Stability found that chlorine in treated water attacks polybutylene from the inside, which helps explain why it can fail with little outside warning. For drains, older neighborhoods like Riverside, Avondale, San Marco, and Ortega often have cast iron, and InterNACHI lists below-ground cast iron waste pipe at 50 to 60 years of life expectancy. Newer homes usually have PVC drains and copper, CPVC, or PEX supply lines.
Age is a clue, not proof. Jacksonville homes get remodeled and partially repiped all the time, so verify what’s actually installed.
Check under sinks, at the water heater, and where the main line enters the house. A remodeled bathroom can have PVC under it while cast iron runs everywhere else.
If you find gray plastic pipe, read our guide to polybutylene pipes and see what polybutylene pipe replacement involves before you negotiate.
Why does the 4-point inspection matter for Jacksonville buyers?
If the home is more than 20 years old, your insurer may want a 4-point inspection before it will write a policy, so plan for it early. Citizens Property Insurance requires a 4-point inspection for applications on properties more than 20 years old, and the report covers the age, type, and condition of the plumbing. Polybutylene is where this gets serious. According to Citizens’ FAQ, homes 20 years old or newer with polybutylene may be eligible if there are no leaks or damage.
For new business on homes over 20 years old, polybutylene is not insurable on its HO-3, HO-8, DP-1, DP-3, and mobile-home forms. Many private carriers also use 4-point inspections and may decline polybutylene or older plumbing, but rules vary by company. Talk to your insurance agent before your inspection period ends, not after. Replacing plumbing is far easier to plan before closing than under a coverage deadline.
The arithmetic matters here. Polybutylene stopped going into homes in the mid-1990s, so nearly any house that still has it is now more than 20 years old. It’s better to know what you have before you’re in the middle of closing.
How do you check for hidden leaks and sewer problems before closing?
Two checks catch problems a walk-through can’t: a camera scope of the sewer line and a water-meter test for hidden supply leaks. The underground sewer is the big miss I see on home purchases. I’ve seen lines that were still draining with roots, deterioration, and bellies inside them. Not every house needs a sewer camera, but if the house is older, has mature trees, has older sewer materials, or has any history of drain problems, strongly consider one.
For the meter test, make sure nothing is using water, including irrigation, the ice maker, and any water softener that might be regenerating. Note the reading at the meter, usually in a box near the street, then check again after an hour or two without running water. If the numbers moved, water is going somewhere, and in a Florida slab-on-grade home that can be a leak under the slab. EPA WaterSense reports that 9% of homes have leaks wasting 50 gallons or more per day.
A home inspection confirms the fixtures drain at that moment. It can’t see inside an underground sewer.
Older materials behind walls or under the house won’t show a symptom during a short inspection, either. Get the seller’s permission through your agent before running either test. If the meter moves, our slab leak detection page explains what comes next.
How old is the water heater?
The manufacture date is usually encoded in the serial number on the tank’s label, though every brand uses its own format. The Department of Energy estimates the average tank water heater lasts about 15 years nationally. With Jacksonville’s hard water, I typically see roughly 8 to 12, so a 10-year-old tank deserves a closer look. JEA’s data shows hardness of about 15 grains per gallon on average, roughly 7 to 22 depending on ZIP code, and that mineral load settles as sediment in tanks. Orange Park is served by Clay County Utility Authority, not JEA, so those figures don’t apply there.
Look for rust at the base and water in the drain pan. I also check the installation itself, because I find drain pans set up incorrectly and relief-valve discharge piping that wasn’t installed properly. A heater can work fine and still have installation issues that need correcting.
Is the home on septic or sewer?
Not every Jacksonville home is on city sewer, so ask. If it’s septic, ask for the system’s age, where the tank and drain field are, when it was last pumped, and any past repairs or records. The EPA says a typical system should be inspected at least every three years and is usually pumped every three to five. A normal home inspection can’t evaluate the underground parts by flushing toilets and looking at the yard.
The Florida Department of Health in Duval County handles septic permits and inspections, so check with the county about the property’s system. We haven’t found a statewide rule requiring a septic inspection when a home sells, so it’s up to the buyer to ask for one. Under Florida Statutes 381.00655, the owner of a working septic system must connect within 365 days of written notice that public sewer is available. Our septic system services page covers diagnosis and repairs.
What buyers often miss on a pre-purchase plumbing check
- Relying only on the general home inspection for plumbing. It’s mostly visual, and the costliest plumbing problems sit inside walls, under the slab, or underground.
- Skipping the sewer scope on an older home or a lot with mature trees. A line can still drain while roots, deterioration, or a belly sit inside it.
- Calling the insurance agent after closing. If a 4-point report flags polybutylene or aging plumbing, you want time to negotiate or plan the fix.
- Assuming updated finishes mean updated pipes. Kitchens and baths get remodeled far more often than the supply and drain lines behind them.
- Not asking whether the home is on septic. A septic system needs its own inspection and records, and sewer availability can trigger a connection requirement under state law.
How RiverCity handles pre-purchase plumbing inspections
We start with the age of the house and then verify what’s actually there. That means identifying supply and drain pipe materials where they’re visible, running a camera inspection of the sewer line from the cleanout, checking the water heater’s age and installation, testing for hidden leaks, and confirming the shutoff valves actually close.
Then we walk you through what we found in plain language, with the camera video to back it up. If something needs attention, such as a polybutylene repipe or a sewer repair, I want you to hear the options honestly, including when a smaller repair is enough. We’re licensed under Florida license CFC1429969 and work from two Jacksonville locations, one on the Southside and one on the Northside.
Any repair comes with a written, upfront quote before work starts, so you have something concrete to bring to negotiations. What drives the cost of the inspection itself is mostly the size of the home, whether a sewer camera scope is included, and whether there’s an accessible cleanout. If you’re under contract on a Jacksonville home, here’s how our real estate plumbing inspections work.