Confirm, narrow, pinpoint
A leak search usually starts after SoCalGas has responded to an odor call or after a homeowner notices the meter moving with everything off. The plumber's first job is to confirm that gas is actually escaping from the house-side piping and not, for example, from a pilot that went out or a burner left slightly on.
From there the work moves from big to small. The plumber isolates sections of piping, tests each one, and then uses close-range methods to find the exact joint, valve or pipe wall that is leaking.
Common leak detection methods
| Method | What it shows | Best for |
|---|---|---|
| Meter test | Whether gas flows with all appliances off | Confirming a leak exists |
| Pressure drop test | Whether a sealed section loses pressure over time | Narrowing the leak to a section |
| Combustible gas detector | Gas concentration in the air near pipes and fittings | Sniffing along exposed piping, walls and attics |
| Leak detection solution | Bubbles forming at a leaking joint | Pinpointing threaded fittings, valves and connectors |
| Bar holes or probe testing | Gas readings in soil along a buried run | Locating underground leaks before digging |
A typical leak search
- Interview and look.The plumber asks when the smell started, where it is strongest, and whether any digging, remodeling or appliance moves happened recently.
- Check appliances first.Connectors, valves and appliance inlets are the most common leak points and the easiest to test.
- Isolate sections.Valves or caps are used to split the system into indoor, attic, underground and yard sections.
- Pressure test each section.A section that holds pressure is cleared; one that drops gets a closer look.
- Pinpoint and mark.Detectors and leak solution identify the exact spot so only that area is opened up.
- Report before repairing.You should hear what leaked, why, and the repair options before work continues.
What drives the time and cost of leak detection
- How much of the piping is exposed versus hidden in walls, attics or soil
- How many branches and appliances the system feeds
- Whether existing valves allow sections to be isolated easily
- Length of buried runs to pools, spas or outdoor kitchens
- Whether drywall, stucco, concrete or landscaping must be opened
- Whether a permit and inspection are needed for the repair
Questions to ask before the search starts
- Which method will you start with, and why?
- Will you isolate and test sections before opening walls or digging?
- How will you mark and photograph the leak location?
- Is the repair priced separately from the detection work?
- Who restores gas service and relights pilots afterward?
Common questions
Can a plumber find a leak without opening walls?
Often the leak can be narrowed to a section first, which limits how much needs to be opened. Some leaks in walls or under floors still require access to repair.
Is soapy water a reliable test?
Leak detection solution on a fitting is a standard pinpoint method, but it only works on joints you can reach and it is not a substitute for a pressure test.
Will SoCalGas find the leak for me?
SoCalGas responds to odor calls and handles leaks on its side of the meter. Finding and repairing leaks on house-side piping is the owner's job, done by a licensed plumber.
General information for Villa Park, not a quote or professional advice. In an emergency, call 911.