Why won’t my water heater light?

Did you know that a gas water heater's pilot light not igniting or staying lit can be a common and frustrating problem? If you've been struggling to light your water heater's pilot, you're not alone. There are several reasons why this issue may occur, preventing your water heater from working properly.

• Residual gas inside the unit can prevent the pilot light from igniting. Allow the unit to sit for at least five minutes before attempting to light it.
• If the automatic igniter isn't working, you may need to manually ignite the pilot using matches or a stick lighter.
• A clogged pilot tube can block the flow of gas to the pilot light, resulting in ignition problems.
• A kinked or damaged flex gas tube can limit the flow of gas to the pilot light and burner.
• A dirty or obstructed thermocouple may not properly detect the pilot flame, causing the pilot light to go out.

Residual Gas Inside the Unit

Before attempting to ignite your water heater's pilot light, it is important to turn the gas off and let the unit sit for at least five minutes. This allows any residual gas to disperse from the lines and inside the unit. If there is any residual gas inside the lines, it can prevent the pilot light from igniting. Turning the pilot control knob to the “Off” position should be sufficient in most cases.

Residual gas can build up in your water heater, causing ignition problems. Letting the unit sit and disperse the gas helps ensure a clean start and increases the chances of a successful ignition.

Automatic Igniter Isn't Working

Most pilot lights have an igniter button that emits a spark to ignite the gas. If the automatic igniter isn't working and you don't see a spark when you press the button, you may need to use matches or a stick lighter to manually ignite the pilot. The igniter button may wear out over time and require replacement.

In some cases, the automatic igniter button on your water heater may fail to produce a spark, making it difficult for the pilot light to ignite. This can happen due to normal wear and tear over time. To determine if the igniter is the issue, try pressing the button and observing if a spark is generated. If you do not see a spark, it's likely that the igniter button needs to be replaced.

Manual Ignition Method

If the automatic igniter is not working, you can still manually ignite the pilot light using matches or a stick lighter. Here's how:

1. Make sure the gas supply to the water heater is turned on.
2. Locate the pilot light assembly, which is typically near the bottom of the water heater.
3. Turn the gas control knob to the “Pilot” position.
4. Hold a lit match or the stick lighter near the pilot assembly.
5. Press the igniter button while holding the match or lighter near the pilot. This will ignite the gas.
6. Once the pilot light is lit, continue holding the gas control knob in the “Pilot” position for about 30 seconds to allow the thermocouple to heat up.
7. After 30 seconds, release the gas control knob and the pilot light should stay lit.
8. If the pilot light does not stay lit, there may be another issue causing the problem.

If you are unsure about manually igniting the pilot light or if the pilot light still won't stay lit after attempting the manual ignition method, it's best to consult a professional plumber or technician to diagnose and fix the issue.

Issue	Cause	Solution
Pilot light won't ignite	Automatic igniter not working	Manually ignite the pilot or replace the igniter button
Pilot light won't stay lit	Automatic igniter not working	Manually ignite the pilot or replace the igniter button

Pilot Tube Is Clogged

One common reason for a pilot light not igniting is a clogged pilot tube. This small metal tube supplies gas to the pilot light. If it becomes clogged with debris, the gas won't flow properly and the pilot won't ignite.

Cleaning the pilot tube is a relatively simple task that you can do yourself. All you need is a needle or thin wire to gently unclog the tube. Insert the needle or wire carefully into the tube and move it back and forth to dislodge any obstructions. Be cautious not to damage the tube while cleaning it.

If you're unsure about performing this task, it's always best to seek assistance from a professional plumber. They have the knowledge and experience to safely clean the pilot tube and ensure that your water heater functions properly.

Pros	Cons
Simple task to perform	Requires caution to avoid damaging the tube
Can potentially solve the issue	May not work if the pilot tube is severely clogged
Cost-effective solution	Not recommended for individuals without plumbing experience

Flex Gas Tube Is Kinked

The flex gas tube plays a crucial role in supplying gas to both the burner and the pilot light of your gas water heater. However, if this tube becomes kinked or damaged, it can disrupt the flow of gas and lead to issues like the pilot light not staying lit.

If you suspect that the flex gas tube is kinked, it's important to address the problem promptly. A kinked tube restricts the gas flow, which can prevent the pilot light from igniting or cause it to go out frequently. In such cases, it's best to engage the expertise of a professional plumber to repair or replace the flex gas tube.

A qualified plumber will assess the condition of the flex gas tube and determine whether it needs to be straightened or replaced. Remember, attempting to fix a kinked flex gas tube on your own can be hazardous, as it involves working with gas lines. It's always better to rely on trained professionals to ensure the safety and proper functioning of your gas water heater.

Problem	Symptoms	Solution
Kinked Flex Gas Tube	– Pilot light won't stay lit – Inconsistent gas flow – Burner ignition issues	Contact a professional plumber to repair or replace the kinked flex gas tube.

Thermocouple Is Dirty or Obstructed

The thermocouple is a vital safety component that detects whether the pilot light of your water heater is lit or not. If the thermocouple becomes dirty or obstructed with dirt and grime, it may struggle to accurately detect the presence of the pilot flame. As a result, it fails to shut off the gas flow and causes the pilot light to go out. This can lead to the frustrating problem of your water heater pilot not staying lit.

One potential solution to this issue is cleaning the thermocouple. Using fine-grit sandpaper, carefully remove any buildup of dirt and grime. Ensure that the thermocouple is completely free from any obstructions. Cleaning the thermocouple may resolve the problem and allow the pilot light to stay lit.

However, it's worth noting that handling the delicate task of cleaning the thermocouple requires expertise. It is recommended to hire a professional plumber who can safely and effectively clean the thermocouple, ensuring that it functions properly once again.

Get Professional Help for Cleaning the Thermocouple

Handling the cleaning of a dirty or obstructed thermocouple can be challenging and delicate. If you're unsure about performing this task yourself, it's best to rely on the expertise of a professional plumber.

A skilled plumber has the necessary experience and tools to safely clean the thermocouple without causing any damage. They can ensure that the pilot light stays lit consistently, resolving the issue of a water heater pilot that won't stay lit.

Thermocouple Is Faulty or Damaged

If your water heater's pilot light fails to ignite or stay lit, a faulty or damaged thermocouple may be the culprit. The thermocouple plays a crucial role in detecting the pilot flame and shutting off the gas flow if necessary. However, if the thermocouple is not bent close enough to the pilot flame or is experiencing any issues, it can result in water heater ignition problems.

To determine if the thermocouple is faulty or damaged, it is best to consult a professional plumber. They have the expertise to test the thermocouple using a multimeter and accurately diagnose whether a replacement is necessary. Attempting to replace the thermocouple yourself can be risky and may lead to further complications.

Replacing the faulty or damaged thermocouple will ensure proper detection of the pilot flame and a reliable gas flow. A professional plumber will handle the replacement process efficiently, ensuring your water heater operates smoothly once again.

Control Valve Is Worn-Out

If you've tried all the troubleshooting steps mentioned above and your gas water heater still won't ignite, there's a possibility that the control valve is worn-out. The control valve is responsible for regulating the gas flow and controlling the pilot light. When it becomes worn-out or damaged, it can prevent the pilot light from igniting and cause your water heater to malfunction.

Replacing a worn-out control valve requires the expertise of a professional plumber. They have the necessary skills and knowledge to safely handle gas lines and install a new control valve. It's important to have this issue addressed by a professional to ensure proper installation and avoid any safety risks associated with working with gas appliances.

If you're experiencing gas water heater troubleshooting issues and suspect a worn-out control valve, it's time to reach out to a trusted plumbing professional. They will be able to assess the situation, diagnose the problem accurately, and provide the necessary repairs or replacements to get your water heater working efficiently again.