Short answer: if you smell gas near your water heater, leave the building immediately without turning anything on or off, and call 911 or SoCalGas at 1-800-427-2200 from outside. After the utility has made the area safe, a licensed plumber can inspect the heater, the gas connector and the venting. If you need water heater repair help in Diamond Bar, that call comes second.
Signs of a gas problem at a water heater
- The rotten-egg odor added to natural gas
- A hissing or whistling sound near the heater or the gas line
- A gas detector or alarm sounding
- Dead plants or bubbling in standing water near an outdoor gas line
- A pilot light that keeps going out, a yellow or flickering burner flame, or soot around the heater
What to do, in order
- Leave right away. Take everyone, including pets, and do not stop to gather things.
- Do not create a spark. Do not flip light switches, use the garage door opener, start a car in an attached garage, or use a lighter or candle.
- Call from outside. Dial 911 or SoCalGas at 1-800-427-2200 from outside or from a neighbor’s home.
- Stay out until cleared. Return only when the utility or fire department says it is safe.
- Then book the inspection. Ask a licensed plumber to inspect the heater, connector and venting before it is used again.
Carbon monoxide is a separate risk
A gas water heater that is not venting properly can release carbon monoxide, which has no smell. Warning signs include headaches, dizziness or nausea that improve when you leave the home, soot or scorch marks around the heater, a heater that backdrafts, or a carbon monoxide alarm. If an alarm sounds or anyone has symptoms, go outside into fresh air and call 911. California requires carbon monoxide alarms in most homes with fuel-burning appliances, so check that yours work.
What a plumber checks afterward
| Item | What is checked |
|---|---|
| Gas connector | Corrosion, kinks, age and fitting tightness, tested for leaks |
| Gas control valve and pilot or igniter | Operation, thermocouple or flame sensor condition |
| Venting and draft | Correct vent type and slope, backdraft test, clearances |
| Combustion air | Openings sized and unobstructed |
| Water leak damage | Whether water has reached the burner chamber or controls, which can require replacement |
| Permit requirements | Gas line changes or replacement may need a permit and inspection in your city |
A wet gas heater is a special case. Water entering the burner compartment can damage the controls and rust the burner, so a heater that has leaked should be inspected before it is relit. If the heater is also leaking water, start with our emergency leak checklist once gas safety has been dealt with, and then call for professional water heater leak repair.
Need a plumber for this? Once the gas utility has cleared the area, call to be connected with a plumber for inspection or replacement.
Call +1 (909) 760-1466If the inspection shows the heater is corroded or badly damaged, see water heater replacement for what a code-compliant installation includes. Gas heaters need correct venting and combustion air for the new unit as well.
Frequently asked questions
What should I do if I smell gas near my water heater?
Leave the building immediately. Do not touch switches or use a flame. From outside or a neighbor’s home, call 911 or SoCalGas at 1-800-427-2200. Do not go back in until it is declared safe.
Can I relight the pilot after a gas smell?
No. Wait until the gas utility has cleared the area and a licensed professional has inspected the heater and connections. A heater that has leaked water also needs checking before it is lit.
Is a hissing noise from the water heater a gas leak?
It can be, but it can also be sediment boiling in the tank or a relief valve releasing steam. If there is any gas odor with the sound, treat it as a gas leak. Otherwise turn off the heat source if safe and call a plumber.
Do gas heater repairs need a permit?
Replacing a water heater or altering the gas line usually requires a permit and inspection in California cities. Rules vary, so ask the plumber and your local building department.
Sources and further reading
Related guides
- Emergency water heater leak repairWhat to do in the first ten minutes, how to find where the water is really coming from, and when to call right away.
- Replacing a leaking water heaterWhen a leak means replacement, what a California-compliant installation includes, and how permits and bracing fit in.
- Flex line and shutoff valve leaksCorroded connectors, seized shutoff valves, and drips at the top of the heater, and how they are usually fixed.