Common Mr. Heater Pilot Light Problems Solved

If you have a little propane heater in your RV, chances are pretty big that it is from the Mr. Heater brand name. Mr. Heater is one of the most popular propane heaters that you can get for an RV.

These are very reliable, efficient, and cost-effective, although they do sometimes have issues. One of these issues has to do with the pilot light. Today, we are here to talk about common Mr. Heater pilot light problems.

By far the most common issue that a Mr. Heater pilot light has is that it keeps going out. Now, there are a variety of reasons why this pilot light on your Mr. Heater keeps going out including issues with the sensor, dirt in the pilot tube, the gas flow restrictor valve being clogged, or an issue with the thermocouple.

5 Common Mr. Heater Pilot Light Problems & Solutions

There are five really common reasons why the pilot light on your Mr. Heater is having issues. Right now, we want to take a closer look at all of them, what could possibly cause these issues in the first place, and how to solve them once they occur. 

common Mr Heater Pilot light problems

Why Does My Pilot Light Keep Going Out On My Mr. Heater?

To be specific, there are five common issues that may cause the pilot light on your Mr. Heater to keep going out. These include issues with the sensor, dirt being in the pilot tube, the gas flow restrictor valve being clogged, a clogged thermocouple, or a worn-out thermocouple.

Let’s take a closer look at each of these issues right now to figure out which it is and how to take care of them.

1. An Issue With The Sensor

All Mr. Heaters come complete with built-in sensors. These sensors are designed as a safety feature and are made to cut off the fuel supply and also cut the flame if it detects that there is some sort of issue. If there is truly some kind of problem, this sensor is actually your first line of defense. 

Of course, if this sensor detects something wrong, it’s going to shut everything down. However, if there is nothing seemingly wrong, but the sensor still shuts everything off, then there are some solutions.


First of all, make sure that there isn’t actually some kind of problem that the sensor is registering, such as the flame that is either too small or too large. 

If there is no actual problem that the sensor is detecting, then you should try to clean it. You want to get some sandpaper and rub off any soot or carbon that has built up on the sensor. 

Remember, soot and carbon both occur during combustion, so this is a likely issue. Once the sensor is clean, try lighting it again. If it lights, just make sure that the flame covers at least half of the sensor so that it can detect it. 

If the sensor cannot detect the flame because it is too small, you’re still going to have problems. If this does not work, unfortunately, it means that the sensor is most likely just broken, and will need to be replaced.

A sensor being broken and requiring replacement is actually very common when it comes to Mr. Heater units.

2. Dirt or Debris in the Pilot Tube

The next common issue that may be causing the pilot light on your Mr. Heater to continuously go off is if there is dirt in the pilot light tube. Keep in mind that the tube that supplies gas to the pilot light is separate from the main gas line. 

Due to combustion and use, dirt and debris can build up inside of it, and therefore cause this pilot light tube may be clogged. This will therefore restrict the flow of gas, and therefore cause the pilot light to go out. On a side note, if the pilot light on your Mr. Heater does not turn on in the first place, then this may also be the problem. 


To check if it is the pilot tube being clogged that is the problem, take a look in the little window that allows you to see the pilot light. If you see a very strong and constant blue flame, then it’s probably not this that is the issue.

On the other hand, if the flame is flickering, or if it is yellowish instead of blue, then it is very likely that the pilot tube needs cleaning.

Thankfully, cleaning the pilot light tube is quite easy. First, you’re going to want to switch off the gas to the heater. Never do this kind of work on your Mr. Heater before first turning the gas flow off. The best thing that you can do to clear out this pilot tube is to get a can of compressed air and blow it into the tube to clear it out.

That said, you might not always have some compressed air on hand, in which case something very thin and sharp like a paper clip or a needle will work. However, you need to be careful here, because if you use too much force, you can damage the interior of that tube.

So, with great caution, take that little pointed object and clear any debris that is in the tube. There is always a chance that the tube is far too clogged up, that the debris is too far down the tube, or that the tube is otherwise damaged.

If any of these are the case, then it is likely that you will just need to purchase a new pilot light tube. Remember that not all pilot light tubes will fit all models, so you do need to get a compatible one.

3. A Clogged Gas Flow Restrictor Valve

Right before the pilot light, you’re going to see a very small valve that controls the pressure of the gas flow. If this is not set correctly, especially for differences between natural gas on propane, it’s not going to work properly.

However, not being properly set usually isn’t the issue. What is the issue however is that these gas flow restrictor valves can become clogged. Just like with a clogged pilot tube, the solution for this problem is much the same.


As a safety precaution, you always want to switch off the fuel before doing any such work. Once you have switched off the fuel, you then want to remove the valve very carefully with the appropriate tools. Once again, the best way to clean this out is by using compressed air. 

However, if you don’t have any compressed air on hand, that pin, needle, or paper clip will do the job. If this was the problem, cleaning out the gas flow restrictor valve should do the trick. If cleaning it out does not work, then this was not the problem.

4. A Clogged Thermocouple

Yet another issue that may be the cause of your pilot light continuously shutting off or going out is if the thermocouple is clogged. In case you didn’t know, a thermocouple is a special type of sensor that measures temperature. If this is the issue, then the solution is quite simple.


If the issue here is indeed a clogged thermocouple, then the solution is to use some fairly fine sandpaper to remove any silt or carbon buildup from the tip of the thermocouple.

If the issue is solved, then you are good to go. If the pilot light still keeps going out, then a clogged thermocouple is not the problem.

5. A Worn Out or Broken Thermocouple

The other potential cause of the pilot light continuously going out is if the thermocouple is worn out or simply broken. If the thermocouple cannot detect the flame or heat coming from the heater, then it’s going to cut off the pilot light for safety reasons. 

This is actually a very important safety feature that all Mr. Heaters come from. It shuts off the fuel supply if it detects that the flame has gone out. This will therefore prevent gas from leaking out and causing a whole host of other issues. If the thermocouple is worn out, dislodged, or broken, you will need to fix it.


If the thermocouple is just loose or dislodged, all you have to do is to first shut down the heater and wait for the inside of it to cool down sufficiently, so you don’t burn yourself.

You’re then going to take the thermocouple in your hands and move it closer to its starting position, where it should be, close to the flame. If this doesn’t fix the problem, then chances are pretty big that the thermocouple is just worn out or broken, or faulty, and therefore needs to be replaced.

How Do You Adjust The Pilot Light On A Mr. Heater?

Of course, if the flame on your pilot light is not large enough, or is too large, then the sensor is going to give you problems. If this is the case, you’re going to need to adjust the pilot light, or to be specific, the size of it. 

To do this, you’re going to need to access the pilot adjustment cap that is located on top of the valve body, which is located just below the gas valve knob. 

Here, you are going to turn the pilot key in the appropriate direction to adjust the size of the flame. Although this may not always be the case, generally speaking, turning it clockwise will make the flames smaller, and vice versa.

Related: Troubleshooting an RV furnace that won’t ignite.

How Do You Clean The Thermocouple On A Mr. Heater?

Unlike some other things that might require water, soap, and brushes, when it comes to the thermal couple on a Mr. Heater, cleaning it simply involves rubbing it with some fairly fine sandpaper. This is in order to remove any buildup of carbon, such, as and other debris.

Can You Light A Mr. Buddy Heater With A Lighter?

Yes, you can light these heaters using a normal lighter. You just have to turn the gas on, hold down the valve, and then use your lighter to light the pilot light. Once the pilot light is lit, you should then be able to turn the gas valve to turn the rest of the unit on.

There you have it, folks, you should not have all of the information you need to about your Mr. Heater, particularly about the pilot light, to solve any issues that it may be having.

Mr. Heaters tend to be quite durable and reliable, but these pilot light issues do seem to be somewhat persistent. That said, other than that, these are great little propane heaters to have for some supplemental heating in your RV. 

Madeline Cooper