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3 Most Common Reasons Why Your Water Heater Burner Isn't Igniting

Hugo Totty is passionate about DIY projects. I love sharing my experiences about different home improvement projects that I've completed.

This article will point out the three most common reasons why the burner on your water heater isn't igniting.

This article will point out the three most common reasons why the burner on your water heater isn't igniting.

Why Won't My Water Heater Burner Ignite Even Though the Pilot Light Is Lit?

When you have a water heater at home, one of the most common issues you have is getting the heater to click on. For many, even a relatively new system can begin to give them needless headaches not long after installation.

One of the most common problems that you might face with getting the water heater to work stems from the pilot light. If you have a water heater pilot light but the burners will not ignite, you need to find out why. The sooner you can solve this issue, the sooner you can make sure you are getting the right kind of heating pumped into your home.

Consider Replacing Your Water Heater System If It's Old

This is typically going to be something to do with the age of your water heater system. For the majority of new systems, a pilot is not used to ignite the heater or the furnace itself. With that in mind, you should absolutely look to make the right decision with regards to replacing the old system that you have in place.

This problem is not something you need to worry about with a newer water heater. Of course, you could have other problems with a new system, but the issue of your pilot light coming on but the burner not igniting will be a thing of the past. You can easily solve this problem simply by taking the time to speak with a professional.

They can usually diagnose the issue for you, though most engineers will likely remind you that you simply get a new system installed to replace your older model.

Troubleshooting the Problem Yourself: 3 Most Common Reasons

Sure, you could just hire an expert to come out and solve the problem. However, many times the issue of the water heater pilot light being lit but burners failing to ignite can be fixed on your own.

The three most common reasons for this happening to you are: 1) a defective gas valve, 2) a rusty thermopile, and/or 3) the automatic shut-off not working as it should.

1. A Defective Gas Valve

So, the most common reason for many people having this problem stems from having a gas valve that is not working as it should. When your gas control valve is faulty, it will mean that your burner is not going to be igniting as it should—or at all.

The main thing to look out for when your gas control valve goes is that the electronics in the valve cannot understand that the pilot has been lit.

The problem here is that if it is your gas valve, then you likely need to replace the entire system. There is no quick fix to this problem, nor is there a small part that you can buy and fit on your own.

In this case, you are probably at the mercy of a professional who can solve the issue for you.

2. A Damaged Thermopile

If your pilot is lighting as it should, but the burner is not lighting, then another common reason for this might be due to a damaged thermopile.

This means that the thermopile is not able to properly sense the flame that is being created. This can happen if the thermopile is being surrounded by rust, which is common in many older systems.

When that happens, the main thing that you need to do is take off the multi-metre and then measure the output that your thermopile is creating. It should be providing a minimum of 350mV.

If you are getting less than this, then you likely need to take out the thermopile from the burner and clean off the corrosion that may have developed over time.

3. A Failed Automatic Shut-Off

The next most common problem for your water heater is going to come down to an automatic shut-off failing to work as it should. This means that the burner will not ignite even though the pilot will remain on.

This is a common problem that likely means you need to get a professional to help you solve the issue—though on the plus side, it will can often be done quickly and cheaply by one. (Although it can technically be solved on your own, it does require some specific technical skills and should probably be left to a professional.)

Keep these above ideas in mind when it comes to your water heater pilot light, and you should have no problems in solving the various problems that they can bring up from time to time.

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.

© 2022 Hugo Totty