You can relight the pilot on most gas water heaters in about five minutes. The steps depend on your unit type, so start there. This is for gas units only, since electric water heaters have no pilot.
No Hot Water? Gas Water Heater or Electric First
Most homes across Rockwall and neighboring Rowlett run on standard gas tank water heaters with standing pilots. A pilot going out after a long idle stretch is one of the most common service calls we get here, and knowing your unit type before you start saves a wasted trip to the garage. If you’re not sure how old your tank is, checking how long a water heater is built to last is worth doing before you spend much time troubleshooting the pilot.
Older tanks use a standing pilot with a manual gas control valve, the knob that also works as your gas shut-off knob. Some newer tanks use a piezo igniter, a push-button spark, instead. Most modern electronic ignition and tankless units skip the pilot entirely, as the table shows.
| Ignition Type | How You Light It | DIY or Call a Pro |
|---|---|---|
Standing pilot, manual valve | Turn the knob, then light the pilot by hand | ✓ Relight it yourself |
Piezo igniter | Hold the knob, press the igniter button | ✓ Relight it yourself |
Electronic ignition | Hot-surface ignition lights it automatically | Call certified technicians |
Tankless unit | No standing pilot at all | Call certified technicians |
If You Smell Gas, Stop and Get Out
This part isn’t optional. Natural gas has no smell on its own, so utility companies add mercaptan, giving a leak a rotten-egg smell. That smell means one thing: leave the house. Don’t flip a light switch or touch the igniter, and don’t go looking for the leak yourself, since gas is heavier than air and settles near the floor right where you’d be standing to relight it.
Once you’re outside, call 911 and Atmos Energy’s 24-hour emergency line at 866.322.8667, the number listed in its own cold-weather safety guidance for DFW customers.
How to Light the Pilot on a Standard Gas Valve
Clear the surrounding area first, especially in a garage installation, since tight garages in a lot of DFW-area homes don’t give a water heater much room to breathe. Clutter can block the combustible air the main burner needs, and a dust buildup can coat the pilot light burner opening.
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Turn the gas knob to OFF.
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Wait the time on your label, since brands differ. Rheem calls for 5 minutes, A.O. Smith and State call for 10. Waiting clears residual gas from the burner chamber.
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Turn the knob to PILOT mode, which keeps the pilot gas valve open enough to feed a small flame at the pilot burner tip.
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Press the knob down, then push the igniter button, or hold a long lighter to the pilot opening until it catches.
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Keep the knob pushed in for 30 to 60 seconds, no shorter. That’s what decides whether the flame stays lit once you let go, since the thermocouple needs that time to heat fully before the valve will hold open on its own. Watch for a steady blue flame rather than a weak yellow one.
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Release the knob slowly, then turn it to ON and set your temperature.
f anything here doesn’t match your tank, follow the manufacturer’s manual instead. The whole process takes a few minutes once the wait passes. If the water still doesn’t reach the right temperature once the pilot’s lit, testing the thermostat’s accuracy is the next thing to check.
Why a Water Heater Pilot Light Won’t Stay Lit
The thermocouple sits right in the pilot light’s flame and makes 20 to 30 millivolts of electricity once it heats up, just enough to hold open the electromagnet inside the gas valve. If it cools even a second before the valve locks in, the pilot goes out. If yours dies the second you let go, it just hasn’t had enough time to heat.
Why It Dies the Moment You Release the Knob?
On an older tank, a worn or dust-caked thermocouple is the most common reason the pilot won’t stay lit. Once the tip gets coated with carbon or starts to degrade, its output drops below what the valve needs, and the pilot dies the second you release the knob. That part is inexpensive and quick for us to swap, and a fifth relight attempt won’t fix a failed sensor.
Why Does the Pilot Keep Going Out?
Drafts near the tank and sudden gas pressure changes can kill a healthy flame even when the thermocouple tests fine. A kinked flex tube on the gas supply line or a clogged pilot tube chokes off gas flow the same way a bad thermocouple does.
If your unit sat unused all summer, a clogged pilot tube is one of the first things we check. Spiders are drawn to the mercaptan smell in the gas supply line, and a pilot tube is an easy place for one to build a web over a few months. It’s a quick clean-out if that’s the culprit, and easy to miss if you’re focused on the thermocouple.
When the Gas Control Valve Is the Problem
The gas control valve itself can fail too, unrelated to the thermocouple, and no amount of holding the knob down fixes that. It calls for a parts and labor repair, and a professional technician can tell within minutes which part is actually at fault.
Combustible Air and Carbon Monoxide Risk
Clutter and a blocked vent are common, fixable reasons a pilot won’t hold, since the main burner and pilot draw on the same air supply. Keeping that path clear is what keeps a water heater working safely, and blocking it is how carbon monoxide ends up in the room instead of going up the flue. If a faint gas smell lingers even after you’ve cleared the area, schedule a gas leak inspection instead of relighting again.
Electronic Ignition Systems and Tankless Units
Electronic and hot-surface ignition, a heating element that lights the burner without a flame or spark, lights on its own, and there’s no pilot to relight by hand on these units or on any tankless unit. Many have a status light near the access panel that blinks an error code by model number. If it won’t ignite on its own, that’s a job for certified technicians, since forcing it just means an extra trip charge once we get there.
Tankless units log fault codes, and reading them is the first step in any diagnostic. On that job, reaching the manufacturer directly was what unlocked the warranty repair, and that takes a tech who knows the model and holds a service account to make the call.
Cold Weather Brings the Pilot-Out Calls
Every year, the first real cold snap across Rockwall and the surrounding DFW suburbs sets off a wave of calls about pilots that won’t relight or won’t hold. These units sit idle for long stretches over summer, and that’s exactly when a weak thermocouple finally gives out.
There’s a particular kind of dread in a cold garage at 6 a.m., flashlight in one hand, trying to get a stubborn pilot to catch before the kids need hot water. A dead pilot is one of the most common plumbing issues we run into in the first week of a cold snap, and a customer’s description of the flame over the phone tells us whether it’s a five-minute fix or a thermocouple swap.
Most aging tanks are still on their original thermocouple, worth remembering if yours hasn’t been replaced in a while.
When to Call a Plumber Instead of Relighting the Pilot
Stop trying to relight it yourself and call a licensed plumber if any of these apply:
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You smell gas, at any point.
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The pilot keeps going out after several attempts.
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The flame is a yellow flame instead of a steady blue one.
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Soot around the burner, or an aging tank where this keeps happening.
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You’re not comfortable working around the gas line or valve at any point in this process.
When a properly relit pilot goes out again, the thermocouple is the first thing we check: continuity at the valve connection, then output voltage with the pilot running, a reading under 20 millivolts is weak, and under 18 means it’s done. If that tests out fine, the next step is checking for drafts and pilot tube flow.
Our Master Plumber, Michael Grose, has worked on gas systems since his apprentice days in 1996, licensed since 2010, so a phone description of the flame is enough for him to know what’s wrong before we show up.
⭐⭐⭐⭐⭐
“Very pleased, with their work. When the winter storm took out our tankless hot water heater, I contacted them. Even though we were not regular customers they came and replaced our heater and got us up and running quickly! They quoted the job before they came over, and everything went exactly as quoted.”
Intown Plumbing has been serving Rockwall and the surrounding DFW area for over a decade. If yours won’t hold after a couple of tries, get it looked at before a bad thermocouple leaves your family without hot water.
Call (469) 207-1400 or book online.
