Not all water heaters use pilot lights anymore

Modern water heaters come in three main ignition types: pilot light, electronic ignition, and tankless systems. A pilot light is a small, continuously burning flame that ignites the main burner when heat is needed. Older gas water heaters almost always had them. Today, most new gas models use electronic ignition instead, which lights the burner with an electric spark only when the thermostat calls for heat. Tankless water heaters and electric models do not use pilot lights at all.

Whether your water heater has a pilot light depends on its age, fuel type, and design. If you have a gas water heater built before 2005, it almost certainly has one. If it was installed after 2010, it probably does not. Electric water heaters never have pilot lights—they use heating elements powered directly by electricity. Understanding which type you own matters because each one behaves differently when something goes wrong and costs differently to operate.

Key Takeaways

  • Gas water heaters built before 2005 typically have pilot lights; most newer models use electronic ignition instead.
  • Electric water heaters and tankless systems do not use pilot lights under any circumstances.
  • A pilot light burns continuously and uses a small amount of gas even when no hot water is being drawn.
  • Electronic ignition systems light only when needed, which is why they became the standard for new gas water heaters.
  • If your pilot light goes out, the water heater will not produce hot water until it is relit.

Gas water heaters with pilot lights

Gas water heaters with pilot lights were the industry standard until the early 2000s. The pilot light is a small flame that stays on all the time, burning a tiny amount of gas. When the water temperature drops below the thermostat setting, the heat from the pilot ignites the main burner, which heats the water in the tank. Once the water reaches the set temperature, the main burner shuts off, but the pilot stays lit and ready for the next cycle.

The downside of a pilot light is that it wastes gas continuously, even at night or when nobody is home. A pilot light typically uses between 400 and 600 BTU per hour, which adds up over months and years. The upside is simplicity—there are no electronic parts to fail, and the system works even during a power outage. If you have an older gas water heater and the pilot light goes out, you can usually relight it yourself by following the instructions on the tank, though some people prefer to call a technician.

Electronic ignition systems in newer gas models

Starting in the mid-2000s, manufacturers began replacing pilot lights with electronic ignition systems. These systems use a spark or hot surface igniter to light the main burner only when heat is needed. The thermostat signals the igniter to fire, the burner lights, and once the water is hot enough, both the burner and igniter shut off. Nothing burns continuously.

Electronic ignition saves gas compared to a pilot light—roughly 30 to 40 percent less fuel over a year. The trade-off is that these systems require electricity to operate, so they will not work during a power outage. They also have more parts that can fail: the igniter itself, the control board, and the wiring. Repairs usually cost more than relighting a pilot. Most gas water heaters sold today use electronic ignition, and many manufacturers no longer make pilot-light models at all.

Electric water heaters have no pilot light

Electric water heaters do not use pilot lights or any kind of open flame. Instead, they have one or two electric heating elements submerged in the tank. When the thermostat detects that the water has cooled, it sends power to the heating element, which warms the water directly. Once the temperature reaches the set point, power cuts off. There is nothing burning, nothing to light, and nothing that can blow out.

Electric water heaters are simpler in some ways because there are fewer moving parts and no gas line to maintain. They are also safer in homes where gas is not available or where ventilation is difficult. The downside is that electricity is more expensive than gas in most areas, so operating costs are higher. Electric models also take longer to heat water and are less efficient at recovering heat after a large draw.

Tankless water heaters and other alternatives

Tankless water heaters heat water on demand rather than storing it in a tank. Most use electronic ignition—a spark or hot surface igniter lights the burner only when hot water is being drawn. Some tankless models are electric and use heating elements instead. None of them have pilot lights because there is no tank sitting idle waiting for the next use.

Heat pump water heaters are another alternative that uses electricity to move heat from the air or ground into the water, similar to how an air conditioner works in reverse. They have no burner and no pilot light. Solar water heaters use the sun to heat water and may have a gas or electric backup system, but the backup is usually electronic ignition, not a pilot light.

How to tell what type you have

Look at the front or side of your water heater. If you see a small blue or yellow flame visible through a window or opening near the bottom, you have a pilot light. If there is no visible flame and the tank is powered by gas, you have electronic ignition. Check the label on the side of the tank—it will say "gas" or "electric" and often lists the year of manufacture. If the label is missing, look at the fuel line: gas models have a gas line running to them; electric models have only an electrical cord or conduit.

If you are unsure, the safest approach is to look at the control panel. Pilot-light models have a straightforward dial with settings like "Pilot," "On," and "Off." Electronic ignition models have a digital display or a more complex control panel with buttons. Tankless models look completely different—they are much smaller and mounted on a wall rather than sitting on the floor.

What happens when a pilot light goes out

If your water heater has a pilot light and it goes out, the main burner will not light, and you will have no hot water. This can happen because of a draft, a faulty thermocouple (a safety device that shuts off gas if the pilot is not burning), or straightforward age. Many pilot lights go out after years of use and need to be relit.

Relighting a pilot is usually straightforward: turn the control dial to "Pilot," hold down the ignition button, and hold a lit match or lighter to the pilot opening. Once it catches, hold the button for another 30 seconds to warm the thermocouple, then turn the dial to "On." If the pilot will not stay lit or goes out repeatedly, the thermocouple may be failing and will need replacement by a technician. If you smell gas while trying to relight the pilot, stop when ready and call your gas company or a professional.

Frequently Asked Questions

Do all gas water heaters have pilot lights?

No. Older gas water heaters (pre-2005) almost always have pilot lights. Most gas water heaters made after 2010 use electronic ignition instead. Some manufacturers still make pilot-light models, but they are less common. Check your tank's label or look for a visible flame to know which type you have.

Can I convert a pilot light water heater to electronic ignition?

Conversion kits exist but are rarely worth the cost. A full conversion requires replacing the burner assembly, control board, and igniter—often $500 to $1,000 in parts and labor. For most people, it is cheaper to replace the entire water heater when the pilot-light model reaches the end of its life.

Does a pilot light use a lot of electricity?

Pilot lights do not use electricity—they burn gas continuously. However, some pilot-light models have an electric igniter to light the pilot initially, which uses minimal power. The main energy cost is the gas the pilot burns, not electricity.

Why do water heater manufacturers stopped making pilot light models?

Electronic ignition is more efficient because it does not burn gas when heat is not needed. It also meets modern energy codes in most states. Manufacturers shifted to electronic systems to reduce operating costs for customers and to comply with regulations, even though pilot-light models are simpler and work during power outages.

What should I do if my water heater pilot light keeps going out?

If relighting it works but it goes out again within hours or days, the thermocouple is likely failing and needs replacement. This is an inexpensive repair—usually $150 to $300 including labor. If the pilot will not light at all, the gas line may be blocked or the igniter may be faulty, and you should call a technician to diagnose it.