Rheem Water Heater Pilot Light Won’t Light – Fixed

The pilot light is an important part of your Rheem water heater, but it might occasionally not light. Usually, relighting the light will restore your water heater’s functionality, but if the light won’t light, there’s a larger issue to address.  

A Rheem water heater pilot light won’t light because of a blocked gas line or a draft in the room. It could also be due to an issue with the pilot light supply tube, a faulty thermocouple, or a dirty gas chamber.

Rheem Water Heater Pilot Light
Rheem Water Heater Pilot Light (Source – https://youtu.be/J1YQI_V_710)

In this article, I’ll discuss some reasons why a Rheem water heater pilot light won’t light and how to fix those problems. Let’s get to it! 

1. You Have a Blocked Gas Line

The pilot light is an essential part of your Rheem water heater. If it goes out, your water heater won’t provide any heat because the pilot light won’t ignite the gas to power the heater. This means that you won’t be able to light your pilot light. 

One potential cause of this issue is that you have a blocked gas line. Gas lines can get clogged by dirt, debris, insects, and tree roots. Additionally, any dents in the pipe can restrict gas flow, and corrosion and rust can also cause problems. 

How To Fix

If you know how to access your gas line, you can inspect it for a blockage. 

If the blockage is not severe, you can usually clear it yourself using a plastic probe. However, fixing a clogged gas pipe can be dangerous, so I recommend consulting a licensed professional from a gas piping company for assistance. 

Rheem Water Heater

2. There’s a Draft in the Room

Sometimes, all it takes is a small breeze to blow the pilot light out. If your water heater is close to an open window or fan, this can make it extremely difficult to light the pilot light and keep it lit. You can try to find the source of the draft by lighting a candle and seeing where the flame flickers.  

If you live in a windy area, air could also come into your home through a chimney, causing the pilot light to go out. If this is the case, installing a chimney cap usually resolves the issue.  

How To Fix

If air is coming through a window, applying weatherstripping can prevent drafts from coming through the cracks. You can also apply weatherstripping to outside doors to eliminate any breeze.

After weatherproofing the room and eliminating any drafts, try lighting the pilot light again. Just be careful when doing so, as incorrectly lighting a pilot light may result in a fire or explosion.   

3. There’s an Issue With the Pilot Supply Tube

Another common reason you may not be able to light your Rheem water heater pilot light is a clogged or faulty pilot supply tube. The pilot supply tube gives the pilot the gas it needs to stay lit, so if it is blocked with something, it won’t be able to ignite because it won’t have enough gas. 

How To Fix

Fixing a clogged pilot supply tube is easy, and you can locate it by referring to the user manual. Use a needle or a piece of wire to remove any dirt or debris. Then, try lighting the pilot light again to see if it has enough gas supply.  

If the pilot light doesn’t light up, the supply tube could be cracked or damaged, and you’ll need to replace it. 

4. You Need To Replace the Thermocouple

The thermocouple is an essential part of your Rheem water heater system. The thermoelectric device controls the gas that flows to the burner, and if it’s broken, it will turn off the gas to the pilot, and you won’t be able to light it. 

How To Fix

Before you replace the thermocouple, test to see if it is the cause of your problem. To do this, test it with a multimeter. If the thermocouple has more than 25 millivolts, it is working properly, and something else is stopping the pilot from staying lit. 

I like this BTMETER BT-90EPC Digital Multimeter from Amazon.com because it can record multiple data, including AC/DC voltage, AC/DC current, resistance, frequency, temperature, and battery. Another benefit is that it has a light sensor, an automatic backlit screen, and an auto-power off.  

Your thermocouple may just need a good cleaning instead of a complete replacement. You can scrub a thermocouple with a sponge or a scouring pad to remove debris and buildup. 

You can call a professional to help you if you need to replace the thermocouple, but it is relatively easy to do on your own.

man repairing Rheem water heater

Here’s how: 

  1. Turn off the gas. 
  2. Turn off the shutoff and control valve.
  3. Allow your Rheem water heater to cool down. I recommend waiting at least five minutes before proceeding to the next step. 
  4. Remove all the covers you need so you can access the burner. 
  5. Unscrew the old thermocouple. 
  6. Install the new thermocouple by replicating how the old one was placed in the burner. The new thermocouple should be identical to the old one in size and length. 
  7. Reinstall the burner covers. 
  8. Reattach all the lines you disconnected in the beginning.  

If this doesn’t work, check out my article on what to do if the pilot light won’t stay lit after thermocouple replacement. In that article, I discuss your next steps in more detail. 

5. The Gas Chamber Is Dirty

Dirty gas chambers don’t allow enough airflow into the chamber, resulting in the pilot not getting the oxygen it needs to extinguish. 

How To Fix

To clean the gas chamber, follow these steps: 

  1. Turn off the power, gas, and water supply. 
  2. Disconnect the thermocouple connector, and gas supply tube. 
  3. Remove any cover panel you need to access the pilot. 
  4. Use a shop vac to clear out any debris. 
  5. Reassemble the chamber and reconnect all the necessary lines. 

If you still have water heater problems after addressing these possible causes, something else might be wrong with your unit. I suggest checking out my article on water heater problems to investigate other options. 


If your Rheem water heater pilot light won’t light or stay lit, this is a sign of a larger issue that you need to address to restore your water heater’s functionality. 

Possible causes include problems with the gas line, pilot supply tube, thermocouple, or gas chamber. Another possible reason is if there is a strong enough draft in the room to put out the light.