Annual Plumbing Maintenance Checklist for California Homeowners (What to Check, and What It Costs)
Most homeowners only think about plumbing maintenance after something has already failed — a water heater that stops making hot water, a slab leak that shows up on the water bill, a slow drain that finally clogs solid. Almost none of that is unavoidable. The parts of a house's plumbing that fail early are, with very few exceptions, the parts nobody ever checked: a water heater that never got flushed, a supply hose that was never replaced, a shutoff valve nobody knew existed until the night it was needed. A short annual routine catches most of it while the fix is still cheap. Here's what to check, room by room and season by season, and where it's worth paying a plumber instead of doing it yourself.
Why this actually matters
Water damage is not a rare, freak occurrence — it's one of the most common and expensive things that happens to a home, and it usually starts small. A 2024 quantitative and qualitative literature review published in Building Services Engineering Research and Technology by Mattsson, Nordquist, Johansson, Bagge and Wallentén examined the documented causes of water damage in buildings and found that failures in service systems, appliances, and wet rooms — not storms or floods — are the dominant source, and that poor monitoring and maintenance routines are consistently among the root causes. You can find the paper via Google Scholar. In other words, the single biggest lever homeowners have over water damage risk isn't luck — it's whether anyone is checking the equipment that's most likely to fail.
Water heater: the highest-value 20 minutes of the year
- Flush a few gallons from the drain valve to check for sediment. In hard-water areas of California, sediment buildup is the main reason tank water heaters lose efficiency and die early — see our guide to water heater flushing and sediment maintenance for how it's done and what a full flush costs if you'd rather have a plumber handle it.
- Check the anode rod every couple of years — it's the sacrificial metal rod that corrodes instead of your tank, and a spent one shortens the tank's life significantly. Our guide to anode rod replacement cost covers when to replace it.
- Test the temperature-and-pressure relief valve by lifting the test lever briefly — it should release water and reseat cleanly. A valve that doesn't trip, or one that won't stop dripping afterward, needs replacing before it becomes a safety issue.
- Look at the strapping if the unit is a tank type — California requires seismic strapping, and it's worth confirming the straps are still tight, not just present.
Under every sink and behind every toilet
- Feel around the shutoff valves (angle stops) under sinks and behind toilets for any dampness, mineral crust, or corrosion, and turn each one a quarter turn closed and back open once a year so it doesn't seize shut when you actually need it in an emergency.
- Check supply lines — the flexible braided hoses running from the shutoff valve to the faucet or toilet — for bulges, kinks, or rust at the fittings. These are cheap to replace proactively and expensive to deal with after they burst, especially the ones feeding a washing machine; see our guide on washing machine hose failure prevention for why those specific hoses deserve extra attention.
- Run a hand along P-traps and drain connections under sinks to check for dampness — a slow trickle here often looks like nothing until it's warped the cabinet floor.
Drains and vents
- Note how fast tubs, showers, and sinks drain. A drain that's noticeably slower than last year is the earliest, cheapest-to-fix sign of a developing clog — waiting until it stops completely usually means a bigger job.
- Listen for gurgling when a fixture drains, which can point to a blocked vent stack rather than the drain itself.
- Have the main sewer line camera-inspected every few years, especially in homes with mature trees nearby or clay/Orangeburg pipe, since root intrusion and pipe deterioration are invisible until they cause a backup.
Outside the house
- Inspect hose bibs and irrigation valves for drips, especially after winter — a cracked hose bib is one of the more common cold-weather casualties even in California's milder climates. See our guide to hose bib repair and replacement cost.
- Walk the yard looking for unusually green or soggy patches that aren't from irrigation — often the first visible sign of an underground leak in a sprinkler line or the main water line.
- Check the water meter with everything in the house turned off: if the leak indicator dial is still spinning, something is using water somewhere. This five-minute check is the single fastest way to catch a hidden leak before it shows up as a shockingly high water bill.
Once a year, know where the shutoffs are
This isn't maintenance exactly, but it belongs on the checklist: confirm you (and everyone else in the household) know where the main water shutoff is, and that it still turns freely. Our guide on main water shutoff valve location covers where to look if you've never located it. A valve that's seized from disuse can turn a minor leak into a flooded house simply because nobody could stop the water fast enough.
What it costs to have a plumber do the whole thing
Most of the checklist above is a free, 30-to-60-minute walk-through you can do yourself. The parts worth paying for are the ones that need tools or expertise: a full water heater flush and inspection commonly runs in the $100–$300 range, a sewer camera inspection is typically a few hundred dollars, and a general whole-house plumbing inspection — where a plumber checks supply lines, fixtures, water pressure, and the water heater in one visit — usually falls in a similar few-hundred-dollar band, varying with home size and access. Compared to the cost of a burst supply line or a water heater that fails and floods a garage or closet, an annual inspection is one of the cheaper insurance policies available for a house.
When the checklist finds something
Catching a problem early is only useful if you act on it before the next issue develops on top of it. If the walk-through turns up unusually high pressure, see our guide on signs of high water pressure and what it costs to fix — sustained high pressure quietly shortens the life of everything else on this list, from supply hoses to the water heater itself. If you found a hidden leak via the meter test, a smart leak detector with automatic shutoff is worth considering so the next one gets caught immediately instead of at the next annual check.
Ready to have a plumber run the full inspection rather than guessing at what you found? Homeowners in Sacramento, Fresno, and Oakland use the same route: request a free quote and get matched with a local licensed plumber.
Need a plumber you can trust?
Tell us about the job — a licensed California plumber gets back to you with a real quote.
Get free quotes