Gas line work: what to know

What the job involves, what changes the price, and what to ask a pro.

What gas line work is

Gas line work runs, repairs or extends natural gas or propane lines to appliances such as ranges, dryers, fireplaces and outdoor grills. A gas line is a safety-critical system, so the work needs a licensed gas fitter or plumber, testing with the right equipment, and a permit in many areas.

Signs you need it

  • You are adding an appliance, such as a range, a dryer, a fireplace or an outdoor grill, that has no gas line at that spot
  • The gas line feeding an appliance is corroded, cracked, or has a loose connection
  • An appliance runs weakly, or the flame is yellow or unstable, which can point to a burner or supply problem and should be checked promptly
  • The gas meter or the regulator is failing, or the line is undersized for the new appliance
  • You smell gas, or a gas detector goes off. Leave the building and call the gas utility from outside.

What the pro does

  • Check the existing gas supply, the meter, the regulator and the line size, and confirm the supply can carry the new load
  • Plan the route, the shutoff valves and the connections for each appliance, and mark the route before any work starts
  • Install the gas pipe with approved materials and fittings, and support it at the correct intervals
  • Install the shutoff valve at each appliance, and the sediment trap where the code requires one
  • Pressure test the new line with the correct test method and gauge before the gas is turned on
  • Turn the gas on, light each appliance, check the flame, and check every joint for leaks with an approved leak test

What changes the price

Every job is different, so we do not publish prices. These are the things that move the quote up or down.

  • Length of the run from the meter to the appliance, and how many turns and fittings it needs
  • Whether the line must be upsized to carry the total load of the appliances
  • Access: a crawlspace, a basement, a finished wall, a slab or a trench outside
  • Number of appliances served and the number of shutoff valves needed
  • Permit, inspection and any utility work needed for the new service
  • Whether an existing line is repaired or replaced, and the condition of the old pipe

What a written quote should spell out

  • Route and length of the new line, with the pipe material and fittings
  • Load calculation or sizing, and whether the existing line is adequate
  • Shutoff valves, sediment traps and connectors at each appliance
  • Pressure test method and result, and the leak test after turn-on
  • Permit and inspection responsibility, and who is licensed to do each part

Questions to ask before you hire

  • Are you licensed for gas work in this area, and who will do the work?
  • Did you size the line for the total load of all the appliances?
  • Which pressure test will you use, and what result do you need before the gas is turned on?
  • Where will the shutoff valves be, and are they easy to reach?
  • Who pulls the permit, and will there be an inspection before the gas is turned on?
  • Will you check the existing line for leaks before you connect the new one?

Red flags

  • Pro who does gas work without a gas license or without the local permit
  • Pro who connects a gas appliance without a leak test on the joints
  • Pro who uses flexible connectors or pipe in a way the appliance or code does not allow
  • Pro who will not show the sizing or the pressure test result

What you can do yourself

Do not run, repair, extend or connect gas lines yourself, and do not turn on a gas line you have not tested, since a gas leak can cause fire, explosion or carbon monoxide poisoning. If you smell gas, leave the building, avoid switches and flames, and call the gas utility from outside. Call a licensed gas fitter or plumber for any gas work.

Licenses and permits

Gas line work is commonly licensed work, and many areas require a permit and inspection for a new or changed gas line. Check with your state or local licensing agency and the local building department about the license and the permit for your work.

Gas line work questions

Can I add a gas line myself to a new appliance?

No. Gas line work commonly requires a license and a permit, and a small leak can be deadly. Hire a licensed gas fitter or plumber, and confirm the permit and inspection before the work starts.

What is a sediment trap, and why does it matter?

It is a short leg at the appliance connection that catches dirt and moisture before they reach the appliance valve. The code often requires one, and the pro should show where it is installed.

How do I know the gas line is big enough?

The line must be sized for the total load of every appliance on it, with the length and the pressure taken into account. The pro should show the sizing calculation before the work starts.

What should I do if I smell gas after the work?

Leave the building right away, do not use switches or flames, and call the gas utility from outside. Do not try to find the leak yourself.

About this guide

This national guide is written and checked by infinibell. Rules and conditions differ by place, so local pros are credited on guides for the cities they serve, not on national ones.

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