If you smell gas, stop reading and leave
If you smell gas, a rotten-egg odor, leave the building right away and move a safe distance. Call the gas utility, for most homes Atlanta Gas Light at 877.427.4321, or 911, once you are outside. Do this before you call a plumber.
Do not try to find the source, relight anything, flip a switch or use a phone or flashlight inside. A pilot that has gone out can let unburned gas collect around the heater, and a spark from a switch is enough to ignite it. Atlanta Gas Light says not to try to stop a leak yourself, and that advice applies to a water heater closet as much as anywhere.
What the pilot and thermocouple actually do
A standing pilot is a small gas flame that stays lit to ignite the main burner when the tank calls for heat. A thermocouple is a short copper-tipped rod that sits in that flame and produces a tiny electrical signal, about the strength of a battery, that holds the gas valve open.
If the thermocouple stops producing that signal because it is worn, coated with soot or poorly positioned, the valve closes and the pilot goes out. That is why a pilot can light when you hold the button down and die the moment you let go.
What the pilot is telling you
How the pilot behaves points to the cause before anyone touches a tool.
Lights only while the button is held
The thermocouple is not generating enough signal to hold the valve open, and it is the most common culprit.
Goes out hours or days later
A draft, a clogged pilot tube or a weak gas supply can let the flame die slowly.
Yellow or flickering flame
A healthy pilot burns blue. Yellow or lazy flames suggest dirt or poor air supply.
Goes out when the furnace or dryer runs
Competing appliances can pull air away from the water heater flue and disturb the flame.
Soot or scorch marks at the base
This is a combustion warning sign, and it means stop and call before relighting.
Safe homeowner checks versus calls for a pro
The left column is limited to what the heater's own label allows a homeowner to do. The right column is where a licensed plumber should take over.
Safe to try yourself
- Confirm there is no gas smell before anything else
- Read the relight instructions printed on the heater label and follow them exactly
- Wait the full time the label states before relighting, so gas can clear
- Relight once, then note whether it holds
- Vacuum dust and lint from around the base with the unit off
- Check that nothing is stored against the heater or blocking the air supply
Call a licensed plumber
- Any gas smell at all, after leaving and calling the gas utility
- A pilot that goes out a second time after a careful relight
- A yellow, sooty or lifting flame, or black marks around the base
- A pilot that lights only while the button is held down
- Replacing a thermocouple, thermopile or gas control valve
- Any work on gas piping, vent pipe or the burner assembly
Why a lit pilot will not stay lit
The usual causes fall into a short list. Each has a different fix, and only some are cheap.
Worn or dirty thermocouple
This is the most common cause. The rod can lose output with age or collect soot, and replacing it is a standard repair for a plumber with the right wrench and a gas leak test afterward.
Clogged pilot tube or orifice
The pilot tube is a thin line that feeds gas to the flame. Dust and rust flakes can narrow it, which starves the flame until it flickers out.
Draft or poor combustion air
A blocked flue, a backdrafting vent or a tight utility room can disturb the flame. On newer tanks with a sealed combustion door, lint on the air screen at the base is a common culprit.
Failing gas control valve
The valve holds the safety and temperature controls in one unit. When it fails, the pilot may not stay lit even with a new thermocouple, and the usual answer is valve replacement or a new heater.
A careful relight, in order
Use these steps only when there is no gas smell, and only if the label on your heater gives matching instructions. The label wins over this page.
Check for gas
Sniff near the heater and floor. Any odor means leave and call, do not continue.
Turn the control to pilot
Set the gas knob as the label directs and wait the stated time before trying again.
Light and hold
Hold the pilot button down for the time the label states, then release slowly.
Watch for stability
The flame should be steady and blue. If it dies, stop and call instead of repeating.
Suwanee note: who handles what when the hot water stops
Atlanta Gas Light publishes 877.427.4321 as its 24-hour emergency line and says to leave the area, avoid ignition sources like phones and light switches, and call from a safe place. We cannot confirm from its pages that it serves every Suwanee address, so look at your gas bill and call the utility named there if it differs.
Gwinnett County Water Resources says it does not control the temperature of the water in your home, and for a lack of hot water the cause is likely the water heater. The pilot problem is yours and your plumber's to solve.
Georgia's plumbing code amendments say gas-fired water heaters and their venting fall under the International Fuel Gas Code. If the pilot problem ends in a new heater, the City of Suwanee lists water heater replacement among the work needing a building permit, and the inspections line is 770-945-8996.
What affects the repair price
A pilot repair can be minor or a sign the heater is near the end of its life. These are the factors that decide which.
The cause
A thermocouple swap is simpler than a gas valve replacement.
Age of the heater
An older tank may cost more to repair than the repair is worth.
Venting condition
A corroded or blocked flue has to be corrected before the heater is put back to work.
Access
A tight closet slows the work.
Timing
Same-day appointments are available when the schedule allows, and after-hours calls can be priced differently from a booked slot.
Homeowners insurance generally covers sudden water damage, not wear on a heater part like a thermocouple. Check the policy for how it treats appliance age.
Want your real number?
Describe the job on the phone and get a clear price before any work starts.
Repair or replace, and where we work
If the diagnosis is a thermocouple or pilot tube, a water heater repair is usually the answer. If the gas valve is failing on an older tank, price a water heater replacement before paying for the valve.
Neighbors in Duluth and Lawrenceville reach the same 24/7 line, and homeowners can also read about tankless water heaters, which use electronic ignition instead of a standing pilot.
Pilot light questions
Only if you smell no gas and follow the instructions printed on the heater label exactly. If the pilot goes out again, stop and call a licensed plumber.
Leave the building, move a safe distance, and call the gas utility, for most homes Atlanta Gas Light at 877.427.4321, or 911. Call a plumber only after that.
That points to a thermocouple that is not producing enough signal. A plumber can test and replace it.
No. Gwinnett County Water Resources says it does not control the water temperature in your home and that a lack of hot water is likely a water heater problem. Call a plumber.
It depends on age and the failing part. A new thermocouple on a working tank is a modest repair, while a failing gas valve on an old tank often points to replacement.