Short definition

Annual plumbing maintenance is a once-a-year homeowner walkthrough — supply lines, fixtures, water heater, shut-offs, drains — to catch failing parts before they fail. Most of it is DIY with $20 in supplies. The WA-specific add-ons are pre-freeze prep in October, hard-water descaling in Eastside / Spokane homes, and crawlspace pipe insulation checks.

What it is

Annual maintenance is observation plus a handful of preventive actions. The standard checklist consolidated across DIY references (Carter, Ug, BD, Taunton, Braveboy):

Indoor walkthrough

  • Inspect every visible pipe run for green corrosion (copper), white scale (calcium), or active drips.
  • Test every supply stop under sinks and at toilets — turn off and back on; should rotate freely. Seized stops are the difference between a 5-minute repair and a flooded floor.
  • Check for slow drains at every fixture; auger or use an enzymatic cleaner as needed.
  • Replace toilet flappers older than 5 years (rubber dries and starts leaking silently).
  • Run a toilet dye test — many WA utilities (SPU, Tacoma Water) give out free dye tablets.
  • Clean P-traps under sinks and tubs — see clean P-traps annually.
  • Descale faucet aerators in vinegar.
  • Check ceilings and walls for water stains; trace any to source.

Water heater

  • Drain a few gallons through the drain valve to flush sediment. Hard-water Eastside / Spokane homes: twice a year.
  • Inspect the anode rod every 3–5 years. Cedar/Tolt soft acidic water eats anodes faster (3–6 years); hard-water Eastside lasts longer.
  • Test the T&P relief valve — lift the lever, water should flow, lever should reseal without dripping.
  • Look for water at the tank base (the early-failure tell).
  • Verify both earthquake straps are tight (WA L&I requires two; see strap water heater WA).

Outdoor / seasonal

  • Inspect hose bibs in spring after the freeze season — split bodies are the #1 spring discovery.
  • Clean gutter downspouts before atmospheric river season (Sept–Nov in WA).
  • Inspect the foundation cleanout for accessibility.
  • Test the sump pump before fall rains by lifting the float.

Pressure check

  • A hose-bib pressure gauge is $10–$15 at any hardware store. See routine water pressure check.
  • Static pressure should be 60–80 psi. Above 80 psi, install a pressure-reducing valve — high pressure breaks fill valves, washing-machine hoses, and faucet cartridges.

Why it matters to a homeowner

Three reasons annual maintenance pays:

  • It catches the silent failures. A toilet flapper that leaks 200 gallons a day is $30–$60/month on a Seattle utility bill before you notice it. A water heater anode rod replaced at year 5 buys 3–5 more years of tank life. A failing supply stop tightened during maintenance saves the replacement during an emergency.
  • It protects insurance claims. Carriers increasingly ask “when did you last inspect?” after a water-damage claim. A documented annual log helps.
  • It’s the foundation for a pre-purchase log. When you sell, a maintenance record signals a cared-for home and supports asking price.

A note on contractor-conversation honesty: a plumber pitching a $400 “annual maintenance plan” that’s mostly visual inspection is selling something you can do yourself in two hours. The pro-walkthrough services that are worth paying for are the ones that include pressure testing, gas-leak detection on appliances, and a backflow visual — the parts that require equipment or training. Ask line-item what’s actually being done, not just “annual maintenance package.”

Cost data

  • DIY annual maintenance: $20–$50 in supplies (vinegar, dye tablets, gauge, replacement flappers).
  • Professional walkthrough: $150–$400.
  • Add-ons (water quality test, scope camera, hydro flush): $100–$500 each.

When to schedule

  • September–October: pre-freeze prep — insulate exposed pipes, drain hose bibs, install frost caps, test sump.
  • March–April: post-freeze inspection — split hose bibs, crawlspace damage, water heater check.
  • Before extended absence (vacation, second home): full inspection plus shut-off main.