If you smell gas, do not read further. Leave first.
SoCalGas says that if you smell natural gas, suspect a leak or see damage, you should evacuate the area immediately and call SoCalGas from a safe location at 1-800-427-2200. Call 911 promptly from a safe location if damage creates a gas leak that may endanger life or cause harm, or if you cannot reach SoCalGas.
Do not flip switches, light a match or try to relight anything while you are inside. Walk outside, then make the call. Once the gas company says it is safe, our 24/7 line can take over the heater.
What a thermocouple does and why it fails
A thermocouple is a short probe that sits in the pilot flame. The heat makes a tiny electrical signal that holds the gas valve open. If the probe wears out, gets sooty or sits out of the flame, the signal drops and the valve closes. The pilot goes out and the heater stops making hot water.
Replacing it is a known repair on standing-pilot heaters. Many newer heaters use electronic ignition and a flame sensor instead, so check your label first. If you are not sure which kind you have, ask a plumber before buying a part.
No pilot and not sure why?
We can check the part, the gas control and the draft in one visit. Ring dispatch and describe what you see.
Symptoms that point to the thermocouple and symptoms that do not
Read across before you open the access panel.
| What you see | Likely thermocouple | Look elsewhere or call |
|---|---|---|
| Pilot lights but dies when you release the knob | Yes, very common | Gas control or draft if it keeps dying |
| Pilot burns weak and yellow | Possible, but the pilot tube may be dirty | Call, since soot can mean poor burning |
| No pilot at all and no gas smell | Maybe | Gas supply, control valve or draft |
| Water leaks from the tank or base | No | Tank failure, so book replacement |
| Smell of gas at any time | Stop | Leave and call SoCalGas first |
A yellow, flickering flame or black soot is a warning sign. Do not keep running the heater.
The swap, once the gas is confirmed safe
This applies to a standing-pilot gas tank heater that is cool, with no gas odor in the room.
- 1
Turn the control to OFF and let it cool
Set the gas control knob to OFF. Close the gas shutoff on the supply line if you can reach it. Wait at least several minutes so nothing is hot.
- 2
Open the access panel
Remove the outer door and the burner cover. Locate the pilot tube, the thermocouple, which is the thin copper line with a tip in the flame, and the gas control.
- 3
Unthread the old thermocouple
Back the nut off at the gas control by hand or with a small wrench. Slide the tip out of its bracket by the pilot burner and take the old part out whole.
- 4
Install the new one
Seat the new tip in the same bracket so it sits in the pilot flame. Thread the nut on by hand, then snug it a quarter turn with a wrench. Do not overtighten.
- 5
Relight by the label
Reopen the gas shutoff, then follow the lighting instructions printed on the heater. Hold the knob for the time stated, then release. The pilot should stay lit.
- 6
Check the connection
Brush soapy water on the fitting you touched. Bubbles mean a leak and the gas goes off right away. Also watch the flame for a clean blue color.
Pico Rivera gas safety, from the utility itself
The source for this part is the SoCalGas emergency information page on socalgas.com, which is the utility's own guidance for what to do if you smell gas. The key point for a thermocouple job is the order of actions. Leave the building, call SoCalGas from outside at 1-800-427-2200, and call 911 if danger exists or you cannot reach the utility.
That means a gas smell halfway through the job ends the job. Do not try to find the leak yourself, do not relight, and do not go back in to turn the knob. Let the gas company clear the home, then bring in a licensed plumber.
Where DIY stops
Be honest with yourself about this list. Any one of these is a reason to hand the job to a pro.
- You smelled gas, even briefly, before or during the job.
- The heater is in a closet or garage with poor ventilation, or you see soot and a yellow flame.
- The pilot will not stay lit after a new thermocouple.
- The tank leaks at the base, which means replacement, not repair.
- The label says electronic ignition and you cannot identify the part.
- You have never worked on gas fittings and feel unsure.
A new thermocouple that fails to hold usually means the gas control valve is the real problem. That is a repair for a plumber and may be a sign that replacement makes sense, so ask us about Water Heater Replacement if the heater is old. Water Heater Repair handles the rest.
Calling a pro in Pico Rivera and nearby
We service gas water heaters across Pico Rivera and nearby towns such as Santa Fe Springs and Norwalk. A clear price comes before the work starts, and same-day appointments are offered when the schedule allows.
If there is no hot water and no gas smell, a thermocouple visit is often quick. If there is any gas smell, use the gas company line first and ours second.
Standards and sources behind this page
Gas safety guidance comes from SoCalGas, and part replacement follows your water heater maker's instructions.
Questions we hear most
The pilot lights while you hold the knob but goes out when you let go. That pattern points to the thermocouple, but it can also be a dirty pilot or a weak gas control.
On a standing-pilot heater with no gas smell, many handy homeowners can. If you are unsure at any point, call a plumber.
Leave the building. Call SoCalGas from outside at 1-800-427-2200, and call 911 if there is danger or you cannot reach the utility. Do not flip switches or relight anything.
Follow the label on your heater. Set the knob to pilot, hold it down while you light the pilot, hold for the time stated, then release.
The tip may not sit in the flame, the pilot may be dirty, there may be a draft, or the gas control may be failing. Stop and have it checked.
If the tank leaks, rumbles or has needed several repairs, replacement is often the better move. Our Water Heater Replacement page explains the signs.
SoCalGas at 1-800-427-2200, from outside the home. Call 911 if there is danger or you cannot reach SoCalGas. Then phone a plumber once the gas company says it is safe.
Pilot out and the house cold?
Our crew works on gas water heaters with the price agreed first. Phone the 24/7 line when the gas is safe.