Selling Your California Home? The Plumbing Issues a Buyer’s Inspector Will Flag — and What to Fix First
Most advice about plumbing and home inspections is written for buyers. Sellers face a different problem: a buyer's inspector is going to walk through the house in a few weeks whether you're ready or not, and whatever they find becomes a negotiating chip — or a request for repairs — during a contingency period when you have the least leverage. Getting ahead of the obvious items before you list, and knowing which ones are worth fixing versus simply disclosing, keeps small plumbing issues from turning into last-minute credits at closing.
Why California sellers can't just skip this
California's Transfer Disclosure Statement (TDS) requires sellers to disclose known material defects, plumbing included, and a separate state law (Health & Safety Code §19211) requires every seller to certify in writing that the home's water heater is braced, anchored, or strapped to resist falling in an earthquake — escrow will typically ask for that certification (the C.A.R. "WHS" form or equivalent) before closing. See our water heater strapping guide for what compliant strapping actually looks like; it's a five-minute check and one of the cheapest things on this list to fix if it's missing.
There's also a financial argument for getting ahead of disclosure rather than hoping an inspector misses something: a widely cited study in the Journal of Real Estate Finance and Economics by economists Anupam Nanda and Stephen Ross examined the adoption of property condition disclosure laws across U.S. states over two decades and found that markets with mandatory disclosure saw average home sale prices rise roughly 3–4% relative to non-disclosure markets — consistent with disclosure reducing the "lemons" discount buyers apply when they suspect sellers are hiding problems (study on Google Scholar). In practice, that means a seller who proactively documents and either fixes or clearly discloses plumbing issues is negotiating from a stronger position than one who lets a buyer's inspector find them cold.
What inspectors flag most often
None of these require a major renovation, but every one of them shows up on a standard home inspection report and gives a buyer's agent language to request a credit:
- Active leaks under sinks — even a slow drip at a supply line or P-trap reads as an ongoing problem, not a one-time event, and often points to a worn supply line or fitting that costs little to replace.
- Running toilets and worn flappers — cheap and fast to fix (see our running toilet cost guide), but an inspector will note it and a buyer will wonder what else wasn't maintained.
- Missing or non-compliant water heater strapping — covered above; escrow can hold up closing over this even when nothing else is wrong.
- Corroded or seized angle stop valves under sinks and behind toilets — a valve that won't turn is a red flag because it means a future leak can't be shut off quickly.
- Water heater age and the TPR valve — inspectors note the manufacture date stamped on the unit; a unit near the end of a typical 10–13-year lifespan (see our water heater lifespan guide) invites a buyer to ask for a credit even if it's currently working fine.
- Signs of a slab leak or old sewer lateral — warm spots on flooring, unexplained water bill spikes, or a home built before 1980 on the original clay lateral are exactly what a sewer camera inspection is built to check before it becomes a buyer's demand mid-escrow. Our slab leak signs guide covers the early warning signs worth checking yourself first.
- Visible galvanized or polybutylene pipe — both were standard decades ago and both are now considered a liability by insurers and buyers alike; see our guide to identifying these pipe types before a buyer's inspector identifies it for you.
- Unpermitted plumbing work — an added bathroom, moved fixture, or water heater swap done without a permit can surface during the buyer's due diligence and complicate the sale; our plumbing permits guide explains what typically requires one in California.
Fix it now vs. disclose and price accordingly
Not everything on that list deserves a check written before you list. As a rule of thumb:
- Fix now, always — anything under a few hundred dollars: running toilets, dripping faucets, missing water heater straps, a seized angle stop. These are cheap, fast, and remove easy negotiating points for almost no cost. A single walkthrough from a licensed plumber to catch and fix this category typically runs a normal service-call range, often $150–$300 for an hour or two of work plus parts.
- Get a number, then decide — water heaters near end of life, a sewer lateral that hasn't been scoped in years, or early slab leak symptoms. A $150–$600 camera inspection or a same-visit water heater assessment gives you a real figure to either fix before listing or disclose with documentation, which is almost always better received than an unexplained "as-is" clause.
- Disclose, don't necessarily fix — large-scale items like a full repipe for galvanized or polybutylene pipe. Buyers of older homes often expect this and price accordingly; sellers rarely recoup a full repipe's cost in sale price, but hiding it (or letting it surface as a surprise) causes far more friction than disclosing it upfront with an inspection report in hand.
The pre-listing plumber walkthrough
The fastest way through this list isn't guessing — it's booking a licensed plumber for a pre-listing walkthrough before your buyer's inspector ever shows up. In one visit, a plumber can check every angle stop and strap, run the water heater's TPR valve, test drain flow at each fixture, and flag anything that needs a closer look (like a camera scope on an older sewer lateral). It typically costs about the same as any other standard service call, and it converts a list of unknowns into either finished repairs or documented, disclosed items — both of which hold up far better in escrow than a surprise on the buyer's report.
Ready to get this checked off before you list? Request a free quote from a licensed California plumber for a pre-listing walkthrough, or start from your city page — sellers in Sacramento, San Diego, and Oakland use the same process to get ahead of their buyer's inspection report.
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