Plumbing Problems Found on Inspection: Sewer, Pipes, and Water Heater

Plumbing problems are among the most common and most expensive inspection findings in California homes. Here's what each finding means and what it costs.

Plumbing issues appear on nearly every inspection report for homes over 20 years old. Some are maintenance items. Others are ticking time bombs that could cost you tens of thousands of dollars if they fail. Here's how to evaluate what your inspector found.

Supply Line (Pipe) Issues

Galvanized Steel Pipes

Standard in homes built before 1960. Galvanized pipes corrode from the inside, gradually restricting water flow and eventually developing pinhole leaks. If your inspector noted low water pressure, rust-colored water, or visible corrosion on galvanized pipes, the system is approaching failure. Full replacement (re-pipe with copper or PEX): $5,000-$12,000.

Polybutylene (Poly-B) Pipes

Used from the late 1970s through the mid-1990s. Polybutylene reacts with chlorine in water and becomes brittle over time, leading to sudden catastrophic failures — not slow leaks, but burst pipes that can flood an entire floor. If your home has poly-B pipes, replacement is strongly recommended. Cost: $4,000-$10,000.

Copper Pipes

Generally reliable for 50-70 years. Common inspection findings include pinhole leaks at joints (repairable, $200-$500 each), evidence of past slab leaks (requires investigation), and corroded connections at water heater or valves (minor repair).

Sewer and Drain Issues

Your standard home inspection does not include a sewer line camera inspection — but you should get one, especially for homes over 30 years old. Common sewer findings in California include:

• Root intrusion. Tree roots penetrate clay or cast iron sewer lines at joints. Clearing costs $200-$500, but the roots return. Permanent fix (lining or replacement): $5,000-$15,000.
• Bellied pipe. A section of pipe has sagged, creating a low spot where waste collects. Requires excavation and replacement of the affected section: $3,000-$8,000.
• Orangeburg pipe. A tar-paper pipe material used from the 1940s-1970s that is now collapsing in many California homes. Replacement: $5,000-$15,000.
• Cast iron deterioration. Cast iron sewer lines (common pre-1970) corrode over time. If your inspector notes "heavy corrosion" or "scaling" in cast iron drain lines, replacement may be approaching.

Water Heater

Water heaters have a typical lifespan of 10-15 years (tank) or 20+ years (tankless). If your inspection notes a water heater past its expected life, budget for replacement: $1,500-$3,500 for tank, $3,000-$6,000 for tankless. Check the data plate for manufacture date — many sellers underestimate or don't know the age.

Also check: is the water heater properly strapped? California requires earthquake strapping on all water heaters. This is a common inspection finding and an inexpensive fix ($50-$150), but it's also something the seller should have done — and may indicate deferred maintenance throughout the home.

What Should Have Been Disclosed

The TDS asks about plumbing system type, condition, and any known issues. A seller who checked "No known plumbing problems" in a home with visibly corroded galvanized pipes or a history of slab leaks has a disclosure problem. Plumbing issues are often chronic and recurring — which means the seller almost certainly knew about them.

Ask specifically: has the seller ever had a plumber out? Have they ever filed an insurance claim for water damage? Were any pipes replaced during their ownership? The answers to these questions should match what's on the TDS.