An earthquake gas shut off valve is a device on your gas line, usually bolted to the pipe just downstream of the meter, that closes automatically when the ground shakes hard enough. In the City of Los Angeles it is not only a smart safety add-on: it is required in some situations. It sits on the building's gas line, so it is part of the gas line work a local plumber does, and it needs a permit in most cases. Here is what it does, what it costs and what to do after a quake. The home page shows the rest of what we arrange.
How does an earthquake gas shut off valve work?
A seismic gas shut off valve senses ground motion and closes the gas line when shaking reaches roughly magnitude 5.4 or higher, according to LADBS. Most residential valves are mechanical: a ball or weight is knocked loose by the shaking and drops to seal the pipe. No power, wires or batteries are needed. Once closed, gas stays off until someone resets the valve.
The valve protects against one specific risk: a gas line breaking or an appliance connector shearing off during a quake, then gas feeding a fire. It does not sense a smell. It does not stop a slow leak from a worn joint. And it is separate from the shutoff valve you may already have at each appliance, and from the valve at the meter that you turn with a wrench.
SoCalGas says its system is resilient in earthquakes and shaking does not typically cause a leak. That is the utility's side of the meter. The valve on your side is a backstop for the piping and appliances inside the building.
Does Los Angeles require an earthquake gas shut off valve?
Yes, in some cases. LADBS requires an approved seismic gas shut off valve when a building permit worth $10,000 or more is issued for a residential or commercial building that has fuel gas piping. Sources also report the valve is part of the sale process for City properties. Confirm your own case with LADBS or the escrow officer.
The valve must be one on the LADBS approved list, and a plumber installing it should know which models are on it. The City list is narrower than the State list, so a valve approved elsewhere in California may not be accepted in Los Angeles. Search the LADBS approved products list for the term "seismic gas" or ask the installer which models they use and whether the model is on the City list.
Remodels trigger the rule more often than people expect. A kitchen remodel with a new gas range, a new addition or a bathroom move that touches gas can push the permit value past $10,000. If your house has gas piping, ask when you apply for the permit whether the valve will be added to the job.
What does it cost to install an earthquake gas shut off valve?
Los Angeles area contractors publish prices of roughly $300 to $800 installed for a typical house, permit included in some quotes. Published lists show about $450 to $550 for a standard meter set outside, and more where the meter is under the house, behind landscaping or needs a field set with a bracing post. Your own quote is the real price.
| Situation | Typical installed price | What moves it |
|---|---|---|
| Standard meter outside the house, clear access | About $300 to $600 | Pipe size, valve model |
| Large home, bigger pipe or higher flow | About $450 to $800 | A high-flow valve costs more |
| Meter under the house, in a curb box or behind plants | From about $550 and up | Access and digging |
| Valve braced to posts in a field set | From about $900 | Posts, bracing, concrete |
A permit is part of the price when the plumber handles it. In Los Angeles the rules are:
- Valve installed before the meter by SoCalGas: no LADBS permit.
- Valve installed after the meter by a qualified installer: a separate LADBS plumbing permit.
- House or duplex with an e-Permit building permit of $10,000 or more: the valve is covered by that permit, with no separate plumbing permit or fee.
Is a SoCalGas rebate or a free valve offer real?
SoCalGas has warned customers about earthquake valve scams and has said it does not currently offer a rebate for these valves. If someone calls, knocks or emails claiming to be from the gas company and offers a free or discounted valve, do not give them access to your property or payment details. Phone SoCalGas yourself at the number on your bill.
Real work follows a plain pattern: a written quote, a named contractor, a CSLB license number you can look up at cslb.ca.gov, a permit where the code needs one, and a valve model that appears on the LADBS list. California also limits a home improvement down payment to $1,000 or 10 percent of the contract price, whichever is less.
Door-to-door sales after a quake or a news story are the usual pattern. Take your time. A valve install is not an emergency, and the plumber gas line cost page shows how other gas jobs are priced.
What do you do after an earthquake if you suspect a gas leak?
Leave the building and take everyone with you. Do not use a light switch, lighter or phone inside. From outside, call SoCalGas at 1-800-427-2200, or 911 if anyone is in danger. SoCalGas advises shutting the gas off yourself only if you smell, hear or see signs of a leak and it is safe to reach the meter.
If you turn off the gas at the meter, leave it off. Only SoCalGas field employees may turn a meter back on. The inside piping and appliances have to be inspected for damage first, and after a big quake the wait can be long because many customers are affected at once.
A tip from SoCalGas that costs little: know where your meter is, and keep a 12-inch or larger adjustable wrench with your emergency supplies near the exit or the meter shutoff. Do not store it hanging on the meter or the pipe.
How do you reset an earthquake gas shut off valve?
Reset steps depend on the model, so follow the instructions on the valve or the maker's sheet. Many mechanical valves have a reset lever, pin or button. Before you reset, check for a gas smell. If you smell gas, leave and call SoCalGas. If the gas at your meter was closed by the utility or by you, leave the meter alone.
When the valve has tripped and you smell nothing, follow the maker steps in order and check for a smell as you go. Appliances with pilot lights may need relighting afterward, so read each appliance label. If the valve trips again at once, there may be a real leak downstream, and a plumber needs to test the piping.
Not sure the quake was what tripped it? Valves can close from a nearby impact or a bump, not only a real quake. A plumber can confirm the valve is working, test the line for leaks and reset it. We'll arrange a visit through the quote page.
Does an earthquake gas shut off valve need maintenance?
Mechanical seismic valves need little. Check the label for the maker's guidance, look at the mounting now and then, and make sure the bracket is firm and the pipe has not shifted. A loose valve may fail to trip properly, or may trip from vibration.
Ask your installer for the model name, the install date and a copy of the permit. Keep them with your house papers. If a plumber finds a gas smell or an appliance fault on the visit, our emergency plumber page explains how urgent calls work. If a valve is old, painted over or damaged by landscaping work, a plumber can look at whether it should be replaced.
Common questions
How long does an earthquake gas shut off valve install take?
A standard install on an accessible meter typically takes a short visit, often a couple of hours, because the plumber shuts off the gas, fits the valve on the pipe, bolts it rigidly, tests for leaks and relights appliances. Harder access, a field set or paperwork can stretch it. The permit and any inspection fit around that. Ask for a time window in the written quote.
What should I ask before I hire someone for an earthquake gas shut off valve?
Ask for the CSLB license number and look it up. Ask which valve model they use and whether it is on the LADBS approved list. Ask whether the permit is in the price and who requests the inspection. Ask what the price covers if the meter is hard to reach. Do not pay more than $1,000 or 10 percent up front.
Does someone need to be at the property?
Usually an adult needs to be home, because the plumber turns off the gas and then relights appliances afterward, such as a water heater pilot or a stove. The meter may be outside, but the appliance check is inside. If you cannot be there, ask the plumber in advance who else can give access and whether gas can be restored without you.