Short definition
A workmanship warranty is the plumber’s written guarantee on their labor — typically 30 days to 1 year on service work, 1 to 5 years on major installs. It’s separate from the manufacturer’s warranty on the fixture or appliance, which covers parts but not the labor to reinstall them.
What it is
Three warranties stack on a plumbing job, and they’re routinely confused:
- Workmanship warranty = the plumber’s labor. If the joint they soldered develops a leak inside the warranty period, the plumber comes back and re-does it at no labor cost.
- Manufacturer warranty = the part. A faucet cartridge with a lifetime warranty (Moen, Delta) gets replaced free by the manufacturer, but the manufacturer doesn’t pay the plumber’s hourly rate to install it.
- Implied warranty = the legal floor. Even without a written warranty, work must meet a reasonable industry standard. WA RCW 19.86 (Consumer Protection Act) and construction-defect case law give you recourse for genuinely defective work, with statute-of-limitations periods up to 12 years from substantial completion for latent defects.
Typical WA durations in 2026: service calls run 30 days to 1 year on labor. Major installs (water heater, repipe, side sewer) run 1 to 5 years. Trenchless sewer lining contractors warranty 5 to 25 years on their install, while the liner manufacturer warranties the material itself for 25 to 50 years.
Why it matters to a homeowner
The warranty is only as good as what’s written down. Verbal promises don’t survive disputes. Six things to verify before signing:
1. Get it on the contract, not in conversation
“We give a 5-year warranty” said in a quote meeting and not on the signed contract is unenforceable in practice. Insist it appears on the written contract with a clear duration and scope.
2. Distinguish the workmanship warranty from the manufacturer’s
A plumber pitching “this water heater has a 6-year warranty” is quoting the manufacturer’s parts coverage, not their own labor coverage. Ask explicitly: “What’s your workmanship warranty on the install labor?”
3. Read the exclusions
Standard exclusions are reasonable: homeowner misuse, frozen pipes from heat being off, earthquake damage, tree-root intrusion in side sewers, washing-machine hose burst. Unreasonable exclusions: “void if homeowner does any plumbing repair anywhere in the home.” Overly broad voiding language is often unenforceable under WA’s Consumer Protection Act.
4. Watch the “lifetime” language
“Lifetime warranty” usually means the lifetime of the original installer at the original install address. It rarely transfers to a next owner. Sometimes it means “as long as we’re in business,” and small contractors come and go.
5. The L&I bond is the backstop
If the contractor goes out of business mid-warranty, you can file a bond claim against their L&I-required $6,000 plumbing contractor surety bond. You can also file on their general liability policy ($250,000 minimum). For pattern misconduct, the WA Consumer Protection Act allows treble damages.
6. Mechanic’s lien math survives the warranty
RCW 60.04 lets subcontractors lien your home for unpaid work even after you’ve paid the prime contractor. A solid prime warranty doesn’t protect you from a sub’s lien if the prime didn’t pay the sub. Lien releases at every progress payment are the protection — independent of the warranty.
When you’ll encounter this term
- Reviewing a written quote before signing.
- Calling a plumber back about a recurring problem — the question “is this still under warranty?” decides who pays.
- A plumber’s marketing material claiming “lifetime warranty” — read the small print.
- After-sale dispute when a plumber refuses to return for re-work — the bond and Consumer Protection Act are leverage.
- Insurance claim after water damage — your warranty status affects recovery.
What a good warranty covers
- Defective workmanship — bad joint, misalignment, code violations
- Reinstall labor for parts that fail under their manufacturer’s warranty
- Diagnostic labor on a recurring issue traceable to the original work
What it typically excludes
- Misuse, abuse, neglect by homeowner
- External causes (freeze, quake, tree roots, hose burst, foundation movement)
- Materials homeowner supplied
- Routine wear (loose handles, scaled aerators)