Water heater not lighting

We don’t ask much from our hot water heaters. We simply want them to provide us with hot water for baths, showers, laundry, and dishwashing. Sooner or later, even the best-cared-for water heater will malfunction. If you have a gas or propane water heater that isn’t giving you hot water, it’s likely that the pilot light has gone out.

If you find that your pilot light has gone out, there are a few things you can try. First, you can try to reignite it, which may be all it takes to fix your problem. If the pilot won’t light, or if it doesn’t stay lit for long, then you may have a more serious issue with your thermocouple or another component.

If you’re experiencing a serious or ongoing problem with your tankless water heater (or the hot water one), you may need to call a professional plumber. At Carter’s My Plumber, we are proud to be a top water repair company in Indianapolis, IN. If you’re in the area and experience a pilot that won’t light, we welcome you to give us a call.

Replacing the Thermocouple

Finding that your pilot light won’t stay ignited can be frustrating, but the good news is, there’s usually a pretty simple explanation. By far the most common cause of a pilot light that won’t ignite is a failed thermocouple. Your thermocouple is a safety feature, built into the water heater. It senses the heat of the pilot and allows gas to flow to the burner. If the thermocouple goes bad then it will shut off the gas, both to your pilot light and to your burner, which means the pilot won’t stay lit.

Replacing the thermocouple is pretty simple, and can often be done in an hour. This is among the simplest of water heater problems, and a skilled plumber can get your unit back up and running with minimal hassle.

Other Reasons for a Bad Pilot Light

While a failed thermocouple is the most likely cause for a pilot light that won’t stay lit, there are a few other options to consider, as well.

There is Residual Gas Trapped in the Unit

If your pilot goes out, we recommend letting it sit for five to 10 minutes so any residual gas can escape from the unit. You don’t necessarily have to turn the gas valve off. Just make sure the control knob on your pilot light is in the OFF position. Let it sit for a few minutes before you try to relight it.

Your Automatic Lighter is Broken

Today’s water heaters usually have automatic igniters, similar to the ones you see on propane grills. Over time, the button itself can become worn down and no longer work, requiring replacement. If the automatic igniter isn’t sparking, you may still be able to light your pilot light with a match or a cigarette lighter.

Your Pilot Tube is Clogged

Another potential problem? Your pilot tube is clogged. This is the small tube that provides the gas needed to ignite your pilot flame, and to keep it lit. With time, this tube may become clogged with debris. It’s usually pretty easy to clean out the tube with a needle or a thin piece of wire. 

Your Water Heater is Old

Finally, just keep in mind that most water heaters don’t last for more than 10 to 15 years. If your heater is already past its prime, it may make the most sense to just replace it, rather than invest in repairs. We are always happy to furnish a price for tankless water heater installation.

Frequently Asked Questions

What does it mean when my gas heater pilot light won’t light?

If a gas water heater won’t light, the first thing to check is to see if there is adequate gas pressure to the water heater. Next we would check the thermocouple/thermopile assembly. After checking that we would check the gas control valve to see if it’s faulty.

Is it dangerous if the pilot light goes out on a water heater?

There is no danger to losing a pilot light. Your gas control valve just won’t be able to fire up.

What’s the best approach to relight the pilot light on a water heater?

Relighting a water heater is very straightforward. Hold down the ON knob on the gas control valve to allow gas to enter the pilot assembly tube, then press the striker to make a spark. Keep pressure on the gas control knob for a minimum of 10-15 seconds.

What is the average water heater igniter replacement cost?

Water heater igniter replacement averages $150.00-$650.00, depending on your model.