Gas Water Heater Installation & Repair in Olympia, WA

Venting

B-vent flue to roof (atmospheric), PVC through wall (power-vent), or dual PVC pipes (direct-vent). Type depends on unit and space.

Gas Shutoff & Drip Leg

Dedicated shutoff valve within 6 feet of unit plus a sediment trap (drip leg) on the gas supply line.

Earthquake Straps

Two straps required — upper and lower third of tank. Washington State code for all water heater installations.

Expansion Tank

Required on all closed plumbing systems to absorb thermal expansion and protect pipes from pressure damage.

Plumbing Permit

City of Olympia and all Thurston County jurisdictions require a permit ($85–$150). Your plumber handles the application and inspection.

CO Detectors

Carbon monoxide detectors required on every level of the home per Washington State law. Your plumber will verify compliance.

Is Gas Available at Your Address?

Puget Sound Energy (PSE) is the natural gas provider for the Olympia area. Most established neighborhoods across the Olympia–Lacey–Tumwater corridor and the Yelm core have gas mains available, and Cascade Natural Gas serves central Shelton. Rural properties around Tenino, Rainier, Rochester, and Littlerock often lack gas service at the street and rely on electric or propane. If you are unsure, your plumber can confirm availability before quoting. Connecting to a new gas main costs $500–$2,000+ depending on distance.

2026 PSE Natural Gas Rates

PSE natural gas rates increased approximately 7% effective January 2026 following Washington UTC approval. The average residential customer using 64 therms per month now pays roughly $90/month for all gas use. Water heating typically accounts for 30–40% of that — approximately $25–$45/month depending on household size and unit efficiency. That is meaningfully less than operating a standard electric tank on PSE electric rates, which rose ~12% in January 2026 to roughly $0.13–$0.15/kWh.

Note: If you want the efficiency of electric without the operating-cost penalty of PSE rates, a heat pump water heater runs approximately $12–$25/month — beating even gas. See our electric water heater page for details.

Gas Water Heater Installation Requirements in Olympia

All gas water heater installations in Thurston County must comply with the Washington State Plumbing Code and local amendments. Requirements include: a metal B-vent flue or PVC power-vent routed to the exterior, a gas shutoff valve within 6 feet of the unit, a drip leg (sediment trap) on the gas supply line, earthquake straps at the upper and lower third of the tank, a thermal expansion tank on closed plumbing systems, a drain pan for indoor installations, and a plumbing permit ($85–$150) pulled by your licensed plumber. Carbon monoxide detectors are required on every level of the home.

Tank vs. Tankless Gas

A standard 50-gallon gas tank water heater costs around $2,500 installed and lasts 8–12 years. A gas tankless unit costs $5,000–$7,000 installed, lasts 20+ years, and reduces water heating energy costs by 24–34%. Gas tankless units with a UEF of 0.82 or higher qualify for a federal tax credit of up to $600/year through 2032. Your plumber will assess your gas line size (3/4" minimum for most tankless units) and venting before recommending a model.

Common Gas Water Heater Repairs

The most frequent gas water heater repair is thermocouple replacement — the safety device that keeps the pilot lit. A failed thermocouple typically costs $150–$300 to replace. Other common repairs include gas valve replacement ($200–$400), burner assembly cleaning ($100–$200), and anode rod replacement ($150–$250). If you smell gas at any time, leave the house immediately, call 911 from outside, then call PSE at 1-888-225-5773. Do not operate any switches or create sparks.