Masterbuilt ThermoTemp XL - model 20051316

Thread resurrectus maximus!

Well so far I have not been able to use this smoker since the only 2 smokes I did with it.

It's an utter piece of garbage and the flame sensor issue that makes the burner go out is becoming more prevalent as more folks have bought this.

Masterbuilt sent me replacement parts for anything mechanical and a thermometer. Unable to get it to stay lit.

Holding the knob in keeps the flame going but it immediately goes out once I let up. I've tried returning the knob slightly, hitting it hard, nada.

Crap product, I'm pissed and going to trash this thing since I can't return it.

That blows. I have been reading more and more from people who have this problem as well. I decided to go with a different smoker. Thanks for an update sorry to hear it didn't work out.

I just put together a thermotemp for my brother's birthday and I had the same "won't stay lit" issue. Lots of internet searching helped very little until I came here.
Long story short, I detached, reattached, and tightened the brass nut until I was about to strip the corners off. It literally can't be any tighter! And I raised the height of the flame sensor about 1/4 inch. Now it works. Just finished seasoning the smoker. Not sure if the flame sensor height or the extreme tightening worked, but one of those did.

Long story long:
I disconnected the thermocouple completely so it was totally separated from the smoker. I was thinking of going to Lowe's or an HVAC supplier to buy a new one, so I needed it in my hand. Then I decided "try to reattach it, that's the quickest solution." So I reattached it. I inadvertently changed the height of the flame sensor and increased the height about 1/4 inch. I tightened the life out of the brass nut at the gas valve, I was just starting to round the corners off the nut actually. And now it works!

I installed a thermocouple on my plain propane smoker as a safety valve, so i can confirm that it's probably the height that made the difference and not the tightening or plumbers tape. The tip has to always be in the flame, not just touching or next to the flame, but actually immersed in flame for it to work.

I have had this smoker (20051316) for about a month now. It is my first gas smoker. Mine takes about 30 seconds of holding the knob to stay lit. Once lit there has never been any trouble staying lit. I do use a wind screen but I have been using a wind screen with my WSM for 15+ years.

I added a gasket to both doors. Without the gasket the smoker maxed at 330-340. With the gaskets it can get up to 360+ depending on the weather. For low my daughter recently did jerky at 150 with no trouble. The dial on mine has a 25 degree offset higher than actual temp measured at the probe. It holds temps extremely well within + - 5 degrees.

Coming from a WSM I love the size and front access. I am still coming to grips on getting the smoke right. Totally different than the WSM. For long cooks the chip pan is way too small and unpredictable. I have been experimenting with a larger chip pan with mixed results as it is still a work in progress. I am going to try a smoke tube on the next cook to see if I can get a reliable smoke for an extended time.

Not sure what the point of the water pan is other than to protect the chip pan. At low and slow the water temp never get hot enough to do much of anything. On the WSM, with an over sized water pan, the water is somewhere between a simmer and slow boil. Drippings mixing with the water vapor add a unique (pleasant) flavor to the bark on long cooks. Something I have yet to recreate on the gasser.

Other things that could be improved:

Put in additional supports for the racks so there is more choice on rack placement.
Loose the glass in the door. Not very useful once a cook is underway and smoke begins to cloud the glass. Adds unnecessary weight to the door.
Stiffen the front frame/hinges so the doors don't sag.

Once I get the smoke figured out I'm looking forward to getting some sleep on the overnighters.

I have had this smoker for about 6 months. Mine lights easily and holds temps within 5 degrees. I ignore what the temp says on the knob and go by a probe.
I agree the chip tray is pretty worthless. I usually fill the chip tray at start up which gives about an hour of smoke. As soon as I see the smoke getting weak I place a smoke tube on the bracket that holds the chip tray (I leave the tray in place)
Last weekend I did chuck shoulders and a butt. It ran within a few degrees of 225 for 13 hours.

Cabo said:

I have had this smoker for about 6 months. Mine lights easily and holds temps within 5 degrees. I ignore what the temp says on the knob and go by a probe.
I agree the chip tray is pretty worthless. I usually fill the chip tray at start up which gives about an hour of smoke. As soon as I see the smoke getting weak I place a smoke tube on the bracket that holds the chip tray (I leave the tray in place)
Last weekend I did chuck shoulders and a butt. It ran within a few degrees of 225 for 13 hours.

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Ignoring the temp would be fine, but the sweet spot is nearly impossible to find once the temp probe goes. Mine historically ran 25 below the markings until today.

Today it has decided that 175 means 150 and 200 means 300. It’s been a long morning of tweaking to find the 179 that means 248-ish (I wanted 240, but I’m not risking it). I guess it is great that I can probably start grilling in this, but that isn’t what I wanted or paid for.

I clean the temp probe with vinegar after every use and have not had a problem holding temp (yet)

Cabo said:

I clean the temp probe with vinegar after every use and have not had a problem holding temp (yet)

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Cleaning the exterior is easy, but I noticed a little bit of buildup inside the probe. If you used vinegar inside, how’d you pull that off? I don’t see how you could soak it since it is horizontal.

Other than the awful waterpan and chip tray, light breeze blowing out the flame, and now this, I’ve been generally pretty happy. I’ve gotten good results with chicken, pork, and brisket.

Diluted vinegar in spray bottle. Leave the rack below the probe in place and put an old rag on it directly under the probe (to catch the drippings). Spray the probe with the vinegar solution. Close both doors and leave the smoker in the sun for 1/2 hour. Wipe the probe with another rag or toothbrush. Might have to repeat if it's really crusty.
I actually clean the entire inside this way.

EVERYONE! I think I found a fix for this Model!!! It actually has nothing to do with the flame sensor! the last several weeks I have been struggling with my 40" thermotemp Masterbuilt smoker not staying lit after lighting just fine. I use this smoker for my food truck aka my job thus this was a major problem for me that i need to fix right away. I followed the manual and stumbled across this forums and have tried others' fixes, but nothing seemed to work, until that last few days I found my own. Instead of the flame sensor being the problem, I believe it has to do with the temperature knob itself, after several attempts of trying to dink with the sensor, I just took the plastic temperature knob off the metal probe sticking out and gave the metal knob several good presses inwards, you can actually feel the knob reset and press back out with more force. and... EVERY single time the next time I ignite it it stay lit! seriously that is all i did, take the temp knob off and give the metal probe a couple good smacks. If anyone sees this thread this smoker is freakin awesome and have used it for years without problems and have continued to use it commercially for my food trailer. But I believe the problem with the smoker not staying lit has to do with the temp knob and not the sensor, if anyone can attest to this please post, thanks!

papajohn77 said:

EVERYONE! I think I found a fix for this Model!!! It actually has nothing to do with the flame sensor! the last several weeks I have been struggling with my 40" thermotemp Masterbuilt smoker not staying lit after lighting just fine. I use this smoker for my food truck aka my job thus this was a major problem for me that i need to fix right away. I followed the manual and stumbled across this forums and have tried others' fixes, but nothing seemed to work, until that last few days I found my own. Instead of the flame sensor being the problem, I believe it has to do with the temperature knob itself, after several attempts of trying to dink with the sensor, I just took the plastic temperature knob off the metal probe sticking out and gave the metal knob several good presses inwards, you can actually feel the knob reset and press back out with more force. and... EVERY single time the next time I ignite it it stay lit! seriously that is all i did, take the temp knob off and give the metal probe a couple good smacks. If anyone sees this thread this smoker is freakin awesome and have used it for years without problems and have continued to use it commercially for my food trailer. But I believe the problem with the smoker not staying lit has to do with the temp knob and not the sensor, if anyone can attest to this please post, thanks!

Click to expand...

Good to see that I'm not the only one with this problem - getting it to stay lit. Lots of people say it's the thermocouple (I'm not mechanically inclined, so is that actually what this MB20051316 uses?), the manual says it's the "temperature wire".

I'll try the Temp Knob solution and see how it works. I assume you're saying that you whack it inwards a few times?

I think this model was about a 50/50 hit/miss-kinda thing. I didn't have any trouble at all with mine once I "got to know it", so to speak. The other issues I had were due to my inexperience with smoking meat in general.

I am gonna give it to my BIL, though...it's WAY too big for my needs now, but he has grown kids/grandkids and will get good use out of it.

Now, if he'll just come get the thing off my back porch so I can have the space for a pizza oven!