Call Southwest Gas first to confirm a gas main can reach you, then apply with a list of your gas appliances and their Btu ratings. Southwest Gas builds and owns the service line and meter. A licensed plumber runs the permitted pipe from the meter to your appliances, and gas turns on after inspection.
Can Southwest Gas reach my house?
Start there, because everything else depends on it. Southwest Gas says its Energy Specialists, at 800-654-2765, can tell you whether you have a natural gas connection, give you a list of licensed plumbing contractors, help with a conversion, and say whether rebates are available in your area.
There are three possible answers:
- A service line already reaches the house. The job may be mostly on your side of the meter.
- A gas main runs in your street, but no line comes to your lot. Southwest Gas builds a new service line from the main to a meter on your property.
- No main nearby. The utility has to extend its main first. That is a bigger project with its own contract, and it often makes sense for a group of neighbors to ask together.
If you're converting from electric or propane, look at how natural gas and propane differ at home before you commit, since appliances are built for one gas or the other.
Who builds which part?
The meter is the dividing line, the same one that decides who fixes what later.
| Part | Who installs it | Who owns and maintains it |
|---|---|---|
| Main in the street | Southwest Gas | Southwest Gas |
| Service line from the main to the meter | Southwest Gas | Southwest Gas |
| Meter and regulator | Southwest Gas | Southwest Gas |
| Pipe from the meter to each appliance (the houseline) | Licensed plumber you hire | You |
| Appliances and connectors | You or your contractor | You |
Southwest Gas's Arizona tariff says the utility "will construct, own, operate and maintain service and main line extensions," with the service line running from its main "to a meter location on the property of the applicant that is satisfactory to the Utility." Past the meter, the tariff puts the pipe on you. The customer must "furnish, install and keep in good, safe and leak free condition a customer piping system." The fuel gas code picks up at the same spot. Phoenix's fuel gas code covers piping "from the point of delivery to the connections with the appliances." Once it's in, see who fixes a gas leak on each side of the meter.
### What does Southwest Gas need from you?
It needs your appliance list. The tariff says that when service is requested, "the applicant will submit a list of natural gas equipment to be used including the Btu input." Pull the rating plate numbers for everything you plan to run: water heater, furnace, range, dryer, fireplace, grill, pool or spa heater. The Btu total tells the utility what capacity the line and meter need, and it drives the money side too.
Where the meter goes is the utility's call. Its tariff says meters are installed "in some convenient location approved by the Utility," placed so they are "at all times accessible for inspection, reading and testing." Tell them where you'd like it, and plan the rest of the job around the spot they approve.
Who pays for the service line?
Southwest Gas pays for part of it, and you may pay the rest. The tariff says extensions are made "on the basis of economic feasibility." The utility works out an allowable investment from the revenue your gas use is expected to bring in, less its cost to serve you, and covers the job up to that amount. If the job costs more, you either advance the difference or pay a nonrefundable facility charge. A few rules matter for homes:
- Your appliance list counts. More gas use means a bigger allowance. The tariff says "No allowance will be made for pool heaters for residential customers," and none for equipment used "for standby or emergency purposes only."
- Advances can come back. Money advanced for a main extension can be refunded, without interest, as other customers connect to it, for up to ten years from when the extension is finished.
- A rough estimate on a main extension is free. On request, the utility prepares "without charge, a preliminary sketch and rough estimate." Detailed plans can require a deposit, and the tariff says those plans come "within 90 days after receipt of the deposit."
- Neighbors can spread the cost. The tariff describes a residential amortization program that may be offered to groups of ten or more homes, paid monthly on the gas bill over no more than five years.
- A meter moved for your convenience is on you. The utility may charge to change a meter location done "solely to suit the customer's convenience."
Get the utility's number in writing before you buy appliances. That figure is Southwest Gas's to set, and it varies with distance and load.
What does your plumber do?
Your plumber designs, permits, installs and tests the houseline. The fuel gas code says gas pipe "shall be sized to supply the full number of outlets for the intended purpose." That's why the plumber wants the same appliance list you gave the utility. A line sized for a range and dryer won't carry a tankless water heater and a pool heater added later.
In Phoenix, the city's planning department publishes a gas clearance table of what needs a permit, developed with the utility and the Arizona Corporation Commission. Phoenix lists this job in the first row: "Any new gas piping installation" needs a permit, with inspection and clearance by the city. The plumber pressure tests the new pipe and the city inspector checks it. Other Valley cities run their own permit offices, so ask which one covers your address. Our guides on who can install a gas line in Arizona and how a gas pressure test works cover both steps.
Standard delivery pressure at the meter outlet is "approximately 0.25 pounds per square inch gauge (7-inch water column)," per the tariff. Higher pressure is supplied only at the utility's option, so your plumber sizes the pipe for standard pressure unless Southwest Gas agrees to supply more.
### How does the gas get turned on?
Southwest Gas turns it on and checks your side first. Its tariff says the utility "shall perform a leak check on the customer's piping system when the gas is turned on," and if uncontrolled hazardous leakage exists, service is denied until the leaks are fixed. It also says the utility "may also refuse service until a certificate executed by an authorized public official or licensed plumber is issued." So have the city clearance and the plumber's test results ready before the turn-on visit. Some utilities outside Arizona ask for a signed gas meter piping pressure test verification form at this step.
Your new service line also gets an automatic safety device. Under 49 CFR 192.383, an excess flow valve goes on new service lines to single-family homes "before the line is activated," with a few exceptions. See what an excess flow valve does and what it won't catch.
What should you plan for later?
Three habits keep a new gas service trouble free:
- Tell Southwest Gas before adding big appliances. The tariff makes it "the customer's responsibility to notify the Utility of changes in their load requirements."
- Know your shutoff. Learn how to turn off the gas at the meter and, once it's off there, leave the turn-on to Southwest Gas.
- Know the emergency steps. If you ever smell gas, leave first, then call 911 and Southwest Gas at 877-860-6020 from a safe place. Southwest Gas's safety page covers the full list.
HQ Plumbing & Air runs new gas lines from the meter to every appliance, pulls the permit, and has the test ready for the inspector. We're licensed and insured, and estimates are free.