Nicolette Forbes

By: Nicolette Forbes on August 8th, 2022

Print/Save as PDF

How to Relight a Water Heater

Standard Water Heaters

Having hot water is great, but what happens when it suddenly disappears? There are several reasons why your water heater is no longer giving you hot water in your home, but one of the big factors is your pilot light going out. 

When a tank-style water heater’s pilot light goes out, it usually means that a change in gas pressure has put the flame out, leaving you with no hot water. It’s important to know how to light your water heater’s pilot light so you can get the flame going again as soon as possible, not only to get your hot showers back but also to make sure no gas gets accidentally released into the house in the event of a broken flame sensor. 

Here at Monkey Wrench Plumbing, Heating & Air, we work with thousands of properties and homeowners on their tank-style water heaters. Through that process, we have helped people just like you figure out how to relight a pilot light on their water heaters. 

In this article, we will discuss: 

  • What a tank-style water heater is
  • What is a pilot light
  • Why a pilot light goes out
  • How to relight the pilot light on your water heater


What Is a Tank-Style Water Heater?

Tank-style water heaters (also known as traditional water heaters, standard water heaters, or conventional water heaters) are the most common water heaters that are found in most homes and are used to heat the water used in your home. It’s typically a large cylinder that holds between 30-to-100 gallons of water, with the most common size for homes usually holding about 50 gallons of water. There are also three types of tank-style water heaters: gas, oil, and electric. 

A Rheem tank-style water heater. 

Tank-style water heaters have a pilot light that heats the water in the tank and continuously keeps it at a constant temperature. Once the hot water runs out from the tank, you will have to wait until the tank refills again to have access to hot water. 


What Is a Pilot Light? 

A pilot light is a small flame in certain gas-fired appliances like your furnace, water heater, and gas fireplace. When you turn on your appliance, gas is released to the main burner, and the pilot light ignites that gas to turn on your appliance and provide heat. The pilot light on your tank-style water heater can usually be found beneath the water tank on your unit. You may need to remove an access panel to access it.

A pilot light knob on a tank-style water heater.

The pilot light is often referred to as a match, similar to how you'd light a fire or gas stove. Without a match, you don't have a fire or a functioning stove. This applies to a pilot light. 

If the pilot light goes out, your gas burner can't ignite, resulting in a lack of hot water. Often, the first clue your pilot light is out is that you don't have hot water. Simply relighting the pilot light will solve the issue, though.


Why Does a Pilot Light Go Out?

The first indicator that your pilot light is out is cold water coming from the hot water tap, but what causes a pilot light flame to go out? 

A pilot light can go out for many reasons: 

  • Change in Gas Pressure

A change in gas pressure is one of the main reasons a pilot light can go out. Although it does not happen often, it does occur, and relighting the pilot typically resolves the problem.

  • Thermocouple

A thermocouple acts as a safety device for your water heater by shutting down the gas valve should the pilot light go out. If your heater's thermocouple begins to have problems, is bent, or dirty, it may shut off the pilot light even if everything else is functioning properly.

  • Air/Draft 

If your water heater's combustion chamber isn't sealed properly, the pilot light can be put out with a breeze, literally. Since the pilot light is simply a small flame, it can easily be blown out if the heater is located in a drafty area.

  • Lack of Combustible Air

Gas appliances, such as water heaters, require air to operate safely. If your unit is located in a closet or other area where it will not have access to the air it needs for combustion, the pilot light may not stay lit.

While it is common for your pilot light to go out every once in a while if it continues to go out, there may be a bigger problem, and we recommend that you call a certified technician for help. 


How to Relight your Water Heater

Uh-oh! Your pilot light has gone out, what do you do? It is possible to relight your pilot light yourself, or you can call a certified technician for help.

If you do decide to relight the pilot light yourself, you should first check if there’s a gas leak, and you can do that by sniffing around. It's key to adhere to the instructions of your water heater since instructions differ between models. 

For the majority of gas water heaters, start by locating the gas shut-off valve on the water heater first. This component is typically labeled near the front lower part of the water heater. Next, turn the knob to the off position. From here, you'll need to wait five minutes for the gas to clear before moving on.

To relight your tank-style water heater yourself, you can follow these steps: 

  1. Remove the water heater access panel.

  2. Make sure the gas valve is open. (On most gas valves, this means the valve is in line with the pipe.)

  3. Put the gas control valve on the water heater to the pilot position.

  4. Press the knob on the front and hold it.

  5. Press the ignitor button (black square button below the knob) until you see a flame appear.

  6. Continue to hold the knob until the indicator light blinks.

  7. Turn the knob to the desired temperature setting.

A pilot light going out once in a blue moon is normal, but several malfunctions in quick succession may signal an issue.

A common cause of extinguished pilot lights is a dirty or bent thermocouple. This part is comprised of a small copper wire and rod that acts as a flame sensor that shuts off the gas if the flame goes out. Do not attempt to relight a water heater pilot light if you smell gas in the area, as it could indicate a gas leak.


Recapping Relighting Water Heaters

Relighting the pilot light on your tank-style water heater can be a breeze and also is possible to do yourself. However, if you smell gas in the area, it could be a gas leak, and we recommend you call a certified technician to help. Additionally, if you find yourself having to relight your pilot light constantly, there could be a bigger issue with your water heater, and it is recommended that you contact a plumber for help.

Want to know more about tank-style water heater upkeep and maintenance? Check out the article below as we dive into how to drain your tank-style water heater.

Six Steps to Drain a Water Heater

We here at Monkey Wrench Plumbing, Heating & Air have been dedicated to giving you the most accurate information to make the best decision for yourself and your home since 2007. If you live in the Los Angeles area and have any further questions on tank-style water heaters or their maintenance, feel free to call us at 310-853-8690, and one of our call center representatives would be happy to help you.