Why Mr Heater Won’t Stay Lit [Reasons + Solutions]

The most common reasons behind your Mr buddy heater keeps shutting off are:

mr heater won't stay lit
  • The dirty pilot or thermocouple.
  • Wrong draft positioning.
  • Malfunctioning gas valve.
  • The clogged pilot orifice.
  • And the faulty flame sensor or electronic spark mechanism.

However, below you will get the easiest and most effective solution to each of these problems. You will never have to face your Mr Heater won’t stay lit issue again. So, let’s get started…

Why Mr Heater Won’t Stay Lit [Reasons + Solutions]

To make your Mr. Heater troubleshooting easy and simple, first, we will tell you why your Mr buddy heater is not staying lit.

mr buddy heater is not staying lit

And then we will provide you with simple solutions, step by step. Okay?  First, collect the following tools to fix your heater problems:

  • A screwdriver set
  • Wrench
  • Microfiber cloth
  • Detergent 
  • Soap water
  • Water hose
  • Scrubs

1. Dirty Pilot

The pilot keeps your heater ignited. If your heater pilot is dirty, the heater pilot light won’t light. So a dirty pilot can be the culprit behind your Mr Heater not staying lit.

mr buddy heater dirty pilot

Carbon, oil, spider web, and other types of debris build-up can be why the pilot light is not working. And as a result, turning off the heater as well.


Cleaning the pilot will bring your gas buddy heater back to life. Here’s how you should do it:

  • Turn off the heater 
  • Use a screwdriver to dislocate the pilot
  • Clear out the dirt and debris with a soft piece of cloth
  • Use a sponge and warm soapy water to clean the pilot thoroughly
  • Clean the pilot with clean water and wipe it with a soft piece of fabric
  • Let the pilot dry properly before installing it back in its place

Wait for a while after installing all the connections to the pilot. Then turn the heater on to see if the ignition is okay now.

2. Improper Draft Positioning

The draft allows air supply in the heater system. The heater works with the help of this air. But if there is too much airflow, then the heater will not stay lit.

Excessive air will blow the fire out. This usually happens if the draft is not fixed correctly. Improper draft adjustment results in the circulation of too much air in the system.


There are a few things you can do to stop air from putting your Mr Heater off. Here they are,

  • Adjust the draft position.
  • Place the heater in an environment where there is no heavy air circulation.
  • Put up a barrier around the heater’s draft.

Try doing any 1 of these 3 things to get your furnace back to working.

3. Dirty Thermocouple

A dirty thermocouple is another culprit behind your mr buddy heater keeps shutting off. The thermocouple signals the heater gas valve when to open and when to close.

mr buddy heater dirty thermocouple

A dirty thermocouple will fail to do it. It will signal the gas valve to close when it is not needed. As a result, the gas supply will stop, and the heater won’t stay lit anymore.


Cleaning the Mr Heater thermocouple is the best option in this case. Here’s how to clean the thermocouple for Mr heater:

  • Turn off the heater fuel supply. Remove the protective flame screen.
  • Remove the thermocouple by unscrewing it. Rinse this thermocouple with cold and clean water.
  • Wipe it gently with a soft piece of cloth. Place it in a dry place to let it dry for 30 minutes.
  • Reattach it once it’s completely dry.

Don’t try Mr. Heater’s thermocouple bypass. It will only bring more trouble for you.

4. Faulty Gas Valve

The gas valve supplies the fuel in your heater. Your heater doesn’t work without this fuel. And this is precisely what happens when the gas valve is faulty.

The gas valve can be broken, or it can be clogged. But whatever the reason may be, your heater won’t stay lit without a gas supply.


Replace the Mr Heater gas valve simply in the following method,

  • Turn off the gas supply. Locate the gas valve near the burner of the heater.
  • Unscrew it from its place. Clean the area with a dry piece of cloth.
  • Place a new gas valve in its place. Then tightly screw the new gas valve. 

Don’t be too rough while unscrewing and screwing the gas valve.

5. Dirty Pilot Orifice

The pilot orifice controls the flow of the gas to the pilot. You already know that if your buddy heater pilot won’t light, the heater will not stay lit.

mr buddy heater pilot orifice

Again, if the pilot orifice is faulty, it will prevent the activity of the pilot. So basically a dirty pilot orifice will eventually cause the whole heater to shut down.


Cleaning the pilot orifice is very easy and highly effective. Here’s how to do it,

  • Turn off all the connections to the heater. Remove the burner shield to access the control knob.
  • Gently pull the control knob to remove it. Then remove the panel behind it to reach the gas valve assembly.
  • Remove the bottom pilot cover to locate the pilot light assembly. Unscrew and remove the pilot assembly.
  • Pull out all the gas lines from that location. Find the pilot orifice there
  • Apply compressed air through the opening till it looks clean.

Now put everything back in its position and turn on the heater. It should work just fine.

6. Faulty Flame Sensor

The flame sensor signals the heater to function appropriately. It reads the atmosphere of the heater and sends commands to the heater system.

faulty flame sensor of mr buddy heater

The sensor will read the wrong signs if it’s dirty. As a result, it will command the heater to turn off. This is the same as the heater not staying lit. 


Cleaning the dirty flame sensor is a piece of cake. You can do it this way,

  • Shut off the heater power. Then locate the flame sensor. Unscrew the flame sensor from its place.
  • Detach all the connections from the flame sensor.
  • Use microfiber to delicately clean the flame sensor rod. Use the brush to clean the dirt and debris clogged in the flame sensor slot.
  • Put the flame sensor back in its place and restore all the connections.

This way, your flame sensor will send accurate signals to your heater system, and your Mr Heater will work the way you want.

7. Faulty Electronic Spark Mechanism

It’s very common for you to hear a clicking sound coming out of your heater. If the noise starts as soon as you turn the blower switch on, it can indicate a faulty electronic spark mechanism.

You can ensure that this is the case by looking into the burner chamber. Visible electronic sparks will be noticeable there.


The solution to this is rerouting the wiring of the heater. You will find the electrical diagram of the heater in the user manual. 

This fix requires you to open up the heater system and re-install the wiring in accordance with the Mr Heater manual. This is a risky task. So it would be better to consult a professional.

And this is all you can do to make sure your Mr Heater always stays lit. Our suggestions are designed for your convenience. You will not have any difficulty if you follow our track.

Here, watching the video will be helpful to know the regular maintenance of your heater.

Mr Buddy Heater Pilot Lights But Not Burner

If your portable Mr Buddy heater won’t turn on even though the pilot light is on, it is sure that the burner orifice is fully or partially clogged with sediment build-up.

mr buddy heater pilot lights but not burner

The main burner orifice is an important part that should be cleaned because from here, the gas is supplied to the burner. 

So, you need to inspect the burner for dust and dirt. Get compressed air and blow air through the port and holes of the burner. You can use a toothpick or the bristles of a toothbrush but avoid using sharp metal while cleaning.

The second most probable reason for burner ignition failure after ODS/pilot lighting is too small burner orifice diameter. Replacing the burner orifice will solve the issue.

Low gas pressure is another major reason for improper combustion, and for that, the burner fails to light. In this case, contact your local gas supplier to solve the issue.


Why pilot light won’t stay lit when I release the knob?

The pilot light won’t stay lit when you release the knob because the thermocouple has gone bad. You know the thermocouple is a safety feature. It stops the gas flow when it senses that the pilot light is gone. But when the thermocouple goes defective, it can’t function and so the pilot light keeps shutting off.  

Why propane heater shuts off after 5 minutes?

Your propane heater shuts off after 5 minutes due to a faulty thermostat, corded or defective flame sensor, pressure switch going to off position, and poor gas supply.

How do you know if you have a bad thermocouple?

If you want to know whether your thermocouple is good or bad, just press the gas supply switch for 30 seconds and see if the flame lights up, only to go out later. The flame going out means that the thermocouple is bad. 

How much does the heater repair cost?

If you consult professionals to fix your propane heater, they will take about $300 to $1,500, depending on the problem.

Will a pilot stay lit with a bad thermocouple?

No, a pilot won’t stay lit with a bad thermocouple.

Why you should not try Mr heater’s thermocouple bypass?

Mr Heater’s thermocouple works to keep the heater safely working. Bypassing it can lead to heavy damage to your heater.

How much does a heater pilot light cost?

You can purchase a good pilot light from amazon for as little as $25.


Now you know why your Mr gas heater won’t stay lit and their solutions. So, whenever you find your Mr heater not staying lit, just follow our solution guide and fix it by yourself.

Besides, you know you can keep your Mr. Heater perfectly working just with proper maintenance. So, don’t forget to maintain your heater regularly. As a result, you will face fewer heater shutting-off issues.

However, if you find yourself in any struggle with any other Mr heater problems, you can let us know in the comment box. We will come to you with the possible solutions ASAP.

About William

William is the founder of Fireplacehubs.com. He has real life practical skills in fixing smoker & heating appliance issues. He loves to share his knowledge & helps others in fixing their appliances & saving their money. William firmly believes that anyone can repair his or her unit with the correct guidance & knowledge. See more at about us.

18 thoughts on “Why Mr Heater Won’t Stay Lit [Reasons + Solutions]”

    • Hi Milo

      The reasons might be a dirty pilot, wrong draft positioning, dirty thermocouple, malfunctioning gas valve, clogged pilot orifice, broken flame sensor, and faulty electronic spark mechanism.


  1. I am on my second Mr Heater Big Buddy, The first one I had nearly a month and it wouldn’t stay lit. Returned before 30 days and got 2nd one, same problem. I have an older model with a fan, which I have had about 7 years and never a problem. The new ones have a problem. Sometimes they work but more often will run 5 minutes and shut off.

    • Hi Laura

      Shocked to hear your 2nd one is also doing a problem. First, try to contact the dealer from whom you got it. If they don’t allow the return, then try to fix it according to our guide.


  2. my mr heater pilot will work and stay on but when i turn the knob to let ppropane in so it will heat up , the pilot goes out ! Do you have a solution ? Thank you

    • Hi Bob

      Check if the gas valve is loose or broken. And fix. Also, check if your heater venting is faulty and there is low gas pressure. I hope, you will get the solution.


  3. I’m curious I have a mr heater. The single can one. An I run it all day just fine. But I have tried to run it all night and it will turn off. Tried not using during the day an only at night but same thing. What could cause it to not run just all night??

  4. Hi,

    My pilot light will stay lit, but when the heater is on it shuts off in 4-5 minutes. It won’t stay lit. What’s the issue?

    • Hi Jason

      Generally, this type of issue happens due to one or more reasons like a dirty pilot or thermocouple, wrong draft positioning, a malfunctioning gas valve, a clogged pilot orifice, a faulty flame sensor, or an electronic spark mechanism.

      Well, to fix your heater shutting-off problem, first, clean the pilot assembly.

      If cleaning doesn’t work, check all the above-mentioned issues one by one to find out the main culprit behind the issue.

      Then, try to fix it following our solution guide in the article.

      Hopefully, your problem will be solved.

      Best of luck!

  5. Hello
    I have a Big Buddy with a 12′ hose assembly going to a 20lb tank. I have 2 tanks and rotate/swap the empty out . Problem is about every other tank the heater wont stay lit. Cant get the pilot to stay lit. Any thoughts?

    • Hi Mike

      Your heater won’t stay lit due to one or more reasons like the dirty pilot or thermocouple, wrong draft positioning, malfunctioning gas valve, a clogged pilot orifice, a faulty flame sensor, or an electronic spark mechanism.

      Well, to fix the problem, inspect all the above-mentioned issues one by one to find out the main culprit. Then, fix it following our solution guide in the article.

      Hopefully, your problem will be solved.

      Best of luck!

  6. Changed the thermocouple on our Sunrite Mr. Heater and as soon as you let go of gas button it shuts off?? Any suggestions

    • Hi Cynthia

      To fix your Mr. heater shutting off issue, as the thermocouple is fresh, now ensure the draft position is okay, the pilot is clean, and the gas valve is clean, or replace the gas valve if you get it defective. Also, make sure the pilot orifice & flame sensor are clean.

      If it doesn’t work, contact the Mr. Heater customer support center.

      Wish you all the best!


Leave a Comment