Top Gas Line Plumbing Companies in Seattle, Washington Ranked

Connecting your home or business to natural gas requires precision, safety, and strict adherence to local codes. Gas line installation and repair is a specialized field of plumbing that involves running pipes from the main utility line to appliances like furnaces, water heaters, stoves, and fireplaces. This work is critical for safety and efficiency, as improper installation can lead to dangerous leaks or carbon monoxide risks. This guide is designed to help Seattle residents and business owners understand the process, regulations, and key considerations for finding qualified local professionals to handle their gas piping needs.

Anthony's Plumbing Company

2624 47th Ave SW, Seattle, WA 98116

Anthony's Plumbing Company is a licensed and insured plumbing service based in Seattle, WA. They provide residential and commercial plumbing solutions including gas line installation, drain repairs, and custom steam shower systems. The company emphasizes clean and professional work practices, using high-quality, safe materials and adhering to all code protocols. They offer free in-home consultations within their service area and have a strong focus on customer satisfaction, building lasting relationships with clients. Their service area includes multiple neighborhoods around Seattle and nearby cities.

5.0

238 Reviews

Wesnor Plumbing and Heating

1705 N 82nd St, Seattle, WA 98103

Wesnor Plumbing and Heating provides a wide range of plumbing and heating services in Seattle, WA, including residential and commercial work. Their offerings cover water heater repair and installation, drain cleaning, sewer camera inspections, hydro jetting, leak detection, repiping, and gas line installation. They are authorized service providers for Rheem and Moen water heaters and hold a gas piping mechanic license, ensuring qualified handling of natural gas services. With extensive experience and licensed, bonded, and insured plumbers, Wesnor emphasizes quality workmanship and customer satisfaction. They also offer rapid response for flooding emergencies.

5.0

131 Reviews

Eco Electric, Plumbing, Heating and Air

126 S Spokane St, Seattle, WA 98134

Eco Electric, Plumbing, Heating and Air provides a range of home services in Seattle, WA, including leak detection plumbing and gas line installation. Serving the Puget Sound area, they offer electrical, plumbing, heating, and air conditioning solutions designed to improve home efficiency and sustainability. Their team brings over 10 years of combined experience and uses advanced technology for detailed inspections and durable repairs. The company is fully licensed, insured, and bonded, and offers financing options to help homeowners manage repair and upgrade costs.

4.9

2.0k Reviews

Pars plumbing

417 212th St SW, Bothell, WA 98021

Pars Plumbing is a plumbing service provider located in Seattle, WA, specializing in water heater repair and installation as well as gas line installation. They focus on delivering efficient and clean workmanship with attention to detail. Pars Plumbing is known for their thoughtful execution and clear communication throughout the project.

5.0

116 Reviews

Pelican Plumbing LLC

4181 Wheaton Wy # 3, Bremerton, WA 98310

Pelican Plumbing LLC is a plumbing contractor based in Seattle, WA, specializing in residential and commercial plumbing services. They offer whole-home re-piping, gas line installations, tankless water heater installation, sump pump repair, drain cleaning, leak detection, and water heater repair. Serving Kitsap County, Gig Harbor, and Tacoma, Pelican Plumbing focuses on high-end remodels, new construction plumbing, and safe, code-compliant gas and propane line installations. With over seven years of experience and union training, they have completed more than 100 projects, providing expert craftsmanship and reliable plumbing solutions.

5.0

109 Reviews

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Understanding Seattle's Gas Line Regulations

In Seattle, all gas line work is heavily regulated to ensure public safety. Unlike some DIY-friendly home projects, working on fuel gas systems is strictly for licensed professionals. The primary governing bodies are the King County Public Health Department's Plumbing and Gas Piping program and the Washington State Department of Labor & Industries (L&I).

A permit is mandatory for any new installation, relocation, or modification of gas piping^{1 2 3}. This is not a mere formality; it triggers a required inspection by King County to verify the work meets all safety codes. The professional you hire will typically manage the permit application process on your behalf through the King County Public Health Permit Center^{3 4}.

Crucially, the individual performing the work must hold a Seattle Gas Piping Mechanic License^{5 6}. This specialized license is required unless you are working on gas piping in an owner-occupied, single-family residence. Always verify this license before work begins, as the installer must present it to the inspector⁵.

The Step-by-Step Process for a Gas Line Project

A professional gas line installation follows a meticulous sequence to ensure safety and compliance from start to finish.

1. Planning and Utility Location Before any digging begins, state law requires a call to 811 (Miss Utility) to have all public underground utilities marked^{7 8}. This free service prevents catastrophic and costly strikes to water, sewer, electrical, or communication lines. The professional will also plan the route from the meter to the appliance, considering distance, obstacles, and the required pipe size.

2. Excavation and Trenching For underground lines, trenching is necessary. In Seattle, all excavation must comply with stringent L&I safety rules designed to prevent cave-ins and protect workers⁹. This may involve shoring, sloping, or using trench boxes. The trench must also be dug to the proper depth as specified by code to protect the pipe from damage¹⁰.

3. Pipe Installation and Corrosion Protection The licensed mechanic will install the appropriate type of pipe-often coated steel (black iron) or corrugated stainless steel tubing (CSST) for indoor runs. For underground ferrous pipe, corrosion protection is essential, which usually involves wrapping the pipe with a protective tape or using pre-coated pipe¹⁰. Where different metals connect (e.g., copper to steel), dielectric fittings must be used to prevent galvanic corrosion¹⁰.

4. Pressure Testing and Purging This is a critical safety step. Once the system is installed but before it's connected to appliances, the professional will conduct a pressure test. The piping system is sealed and pressurized to 1.5 times its normal operating pressure to prove it is gastight¹⁰. After passing the test and inspection, the system must be properly purged of air before the gas is introduced for final appliance connection⁸.

5. Inspection, Backfill, and Restoration A King County inspector will visit to check the entire installation against code^{2 10}. Only after the work passes inspection can the trench be backfilled and the landscape or hardscape restored. The professional handles scheduling this inspection and will not consider the job complete until it has official approval.

Critical Safety Protocols for Gas Piping

The rules surrounding gas work exist for life-saving reasons. Adhering to these protocols is non-negotiable.

• No DIY Gas Work: The complexity and danger of gas systems cannot be overstated. This is not an area for homeowner experimentation. Always hire a licensed Seattle Gas Piping Mechanic^{1 2}.
• Leak Detection: Never use an open flame to check for a gas leak⁷. Professionals use specialized leak detection solutions or electronic gas sniffers. If you smell gas (a rotten egg odor), leave the area immediately and call your utility company from a safe distance.
• Appliance Shutoff Valves: Code requires an accessible, individual shutoff valve for each gas appliance¹⁰. This allows you to safely turn off the gas to a single appliance for maintenance or in an emergency without affecting the rest of the system.
• Consider Excess Flow Valves (EFVs): For new or replaced service lines, discuss with your contractor the installation of an EFV¹¹. This safety device automatically shuts off the gas flow if a significant leak occurs downstream, potentially mitigating the severity of an incident.
• Code Compliance is Paramount: Professionals don't just follow code to pass inspection; they do it to prevent leaks, fires, and carbon monoxide poisoning^{1 2}. Their expertise ensures your system is safe for the long term.

What Influences the Cost of Gas Line Work?

The cost for gas line services in Seattle is not a flat fee; it varies based on several project-specific factors^{1 12}.

• Project Complexity: The single biggest cost driver is often the distance from the gas meter to the appliance. A line for a kitchen stove directly opposite the meter on an exterior wall is far less involved than running a line to a new fireplace on the other side of the house. The number of appliances being connected and the difficulty of the trenching route (e.g., through concrete, under driveways, or rocky soil) also significantly impact the price^{13 10 12}.
• Professional Expertise: The cost includes the value of the professional's license, insurance, experience, and their management of the entire process-from pulling permits to scheduling and passing inspections. This expertise guarantees safety and compliance, justifying the investment^{13 6}.
• Materials: The type, diameter, and length of piping needed, along with the required fittings, valves, and protective materials, contribute to the overall cost¹².

Choosing the Right Professional in Seattle

Given the high stakes, selecting the right contractor is crucial. Start by confirming they hold an active Seattle Gas Piping Mechanic License. Ask if they will handle the King County permit and inspection process directly. A reputable professional will be happy to explain the steps, provide a detailed written estimate that accounts for potential complexities, and show proof of insurance. Look for established local companies with strong reviews specifically related to gas line projects, as this niche requires distinct expertise from general plumbing.

Frequently asked questions

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