Why Your Water Heater's Pilot Light Won't Stay Lit

There are a few possible issues within your plumbing system that may arise due to several different potential sources, and one example here is when your water heater’s pilot light won’t stay lit. The pilot light serves an important role in the water heater and certain other gas appliances, and issues where it won’t stay lit can be both frustrating and time-consuming if you don’t know what you’re looking for.

At My Buddy the Plumber, pilot light issues are just one of several areas we assist clients with when it comes to our quality water heater repair services (we also offer replacements and new installations, including modern tankless water heater options). Why is the pilot light important, and what are some of the reasons your pilot light won’t stay lit? We’ll go over all this, plus some tips on how to remedy the pilot light issue — either on your own or, if you aren’t comfortable with any element here, with the help of our team of plumbers.

Importance of Water Heater Pilot Light

Within a water heater and certain other gas-fired appliances, the pilot light refers to a small flame that’s always burning. This is usually located near the bottom of the unit, and its purpose is to serve as an ignition source for the main burner.

When you need hot water, the pilot light will ignite the main burner and heat up the water within the tank to your desired temperature; when you don’t need hot water, the pilot light will stay lit but the main burner will be off.

Pilot light issues are a common problem many homeowners face at some point or another, and as we’ll discuss in more detail below, there are several reasons this may happen. Fortunately, most of these issues can be remedied without too much difficulty — and we’ll dig into them starting below.

Dirty Pilot Tube

An important component of the pilot light setup is the pilot tube, which is a small tube that supplies the gas to the pilot light. If this becomes dirty or clogged, it can cause the pilot light to go out.

This is a fairly easy problem to remediate on your own, but you will need to exercise caution as you’ll be working with gas. First, locate the shutoff valve for your water heater and turn it to the “off” position. Then, find the pilot light access cover — this will be located on the front of the unit, near the bottom.

Open up this access cover and use a wire or pipe cleaner to clear out any debris that may have accumulated in the pilot tube. Once you’ve done this, reassemble the unit and turn the shutoff valve back to the “on” position. You should now be able to relight your pilot light successfully.

If you’re not comfortable working with gas, or if you can’t seem to clear the pilot tube no matter what you try, it’s best to call in a professional plumber for help.

Thermocouple Problems

Another possible issue here is with your thermocouple, which is a safety device that’s designed to shut off the gas flow if the pilot light goes out. There are actually multiple different issues that can take place within this component:

• Obstruction: In some cases, dirt or other particles block the thermocouple from receiving an electrical signal from the pilot light. As a result, it may shut off the gas flow even when the pilot light is lit. You can clean off the thermocouple with a wire brush to remove any dirt or debris that may be obstructing it.
• Damaged Wire: The wire connecting the thermocouple to the control valve can also become damaged, which will cause the same issue as an obstruction. You’ll need to inspect the wire for any signs of damage and, if necessary, replace it with a new one.

Flex Tube Kinks or Blockages

Yet another important part of the pilot light setup is the flex tube, which provides fuel to the pilot light. Over time, this tube can become damaged or blocked, which will cause the pilot light to go out.

You can inspect the flex tube for any signs of damage (such as kinks) and replace it if necessary. If the flex tube is simply blocked, you’ll need to clear out the blockage and then test the pilot light to see if it stays lit.

If you’re not comfortable working with any of these components, or if you can’t seem to identify the problem, it’s always best to call in a professional for help.

Main Control Valve

Finally, one of the least desirable scenarios here is that the main control valve — which is responsible for supplying gas to the pilot light — is damaged and needs to be replaced. This is a more involved repair and will require you to shut off the gas supply to your water heater before proceeding.

If you’re not comfortable working with gas, it’s best to call in a professional. However, if you’re handy and want to try to tackle the repair on your own, you can find detailed instructions online or in your water heater’s manual.

In some cases, you may be able to clean or adjust the main control valve to get it working properly again. However, if it’s damaged beyond repair, you’ll need a new one.

Once more: If you’re uncomfortable with any of the steps we’ve outlined for any of these issues, or if you simply want some peace of mind, calling in our plumbers is the right way to go. We’ll diagnose the issue and repair it quickly, without any risk of safety or worsening the issue.

For more on this or any of our plumbing, HVAC and electrical services, call the pros at My Buddy the Plumber today.