Huge temperature fluctuations in my masterbuilt propane smoker

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Travereno

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Original poster
May 17, 2020
5
1
Hello everyone. I am a long time reader of this forum and a first time poster. I have a Masterbuilt mb20050211 propane smoker. I've had it for almost a year and have always had temperature issues with it. So far the mods I've made are:

Using an 8" cast iron pan on top of the stock chip pan

Replaced the stock water pan with a disposable catering tray

I'm also using a Bluetooth thermometer to monitor the temp

No matter how hard I try, I cannot keep the temperature stable. For example, if my target is 225, I will preheat and it will hold for a bit, but then the temp will shoot up after cooking for a bit, sometimes to over 260 or more. Then it becomes a constant battle of adjusting the knob and cracking the door to lower the temperature, only to have the temperature fall to under 200. Its a vicious cycle. My smokes generally are successful but I shouldn't have to keep going out and messing with the smoker every 10 minutes to get my meats to cook at the right temp. Overnight smokes are pretty much impossible unless I set an alarm every hour. I'm suspecting the wood chips are burning too fast/hot but I'm not sure whats normal and whats not. Are there other mods or suggestions I can do to the smoker to help stabilize the temperature? Or am I doing something wrong? Any and all help is really appreciated.
 
You should try and get something like an inkbird that will chart the temps and leave it unless it spikes to 300. Id be curious if it goes 225 to 260 then down once the chips are gone or something else.

I run charcoal but my WSM actually does best around 250-260 and the foods always great, so If you just run closer to 250 I wouldn’t fret. It’s the wild swings, like225 then 300 then 200 that I’d be concerned about. But going 225-250 then down won’t ruin any food
 
Two things I noticed on my propane smoker: temps would spike when chips ignited and temps would spike when the water pan dried out. Are those things happening?

I would just use chunks in the pan or foil packets of chips with holes poked in the top.

What happens when your temp goes up? Does it come back down or does it settle in again? If you’re messing with it every 10 minutes you might not be getting the feel of what’s really happening. Don’t sweat temp swings either, as long as they are within a range you’ll be fine.
 
You might consider installing a needle valve to adjust the gas flow. The finer adjustment makes it a bit easier to dial in the temp, although it still is going to drift. Search the forum and you should be able to find the part # and installation details.
 
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Two things I noticed on my propane smoker: temps would spike when chips ignited and temps would spike when the water pan dried out. Are those things happening?

I would just use chunks in the pan or foil packets of chips with holes poked in the top.

What happens when your temp goes up? Does it come back down or does it settle in again? If you’re messing with it every 10 minutes you might not be getting the feel of what’s really happening. Don’t sweat temp swings either, as long as they are within a range you’ll be fine.

The chips may be igniting. I don't ever see a flame with them but can see coals. I've also seen ideas that people line the inside of the cast iron pan with foil. I'm gonna try both. Usually once it spikes, I go outside and try to fix it. I've never let it just sit for a long time. I try to keep it between 225-250, but regularly I'm seeing spikes of 260-300 when it happens. It could very we be the chips.
 
You might consider installing a needle valve to adjust the gas flow. The finer adjustment makes it a bit easier to dial in the temp, although it still is going to drift. Search the forum and you should be able to find the part # and installation details.

Thank you. I'll look into that. I never considered the gas flow to be an issue.
 
I started with propane smokers and like you I was constantly making adjustments. I got a needle valve and it did help. I eventually learned two things. There is no need to freak out about reasonable temp swings, typical ovens swing 30 degrees in either direction. I also learned that propane wasn't for me. I have bought around 10 smokers/grills since and none of them have been propane.
 
Hello everyone. I am a long time reader of this forum and a first time poster. I have a Masterbuilt mb20050211 propane smoker. I've had it for almost a year and have always had temperature issues with it. So far the mods I've made are:

Using an 8" cast iron pan on top of the stock chip pan

Replaced the stock water pan with a disposable catering tray

I'm also using a Bluetooth thermometer to monitor the temp

No matter how hard I try, I cannot keep the temperature stable. For example, if my target is 225, I will preheat and it will hold for a bit, but then the temp will shoot up after cooking for a bit, sometimes to over 260 or more. Then it becomes a constant battle of adjusting the knob and cracking the door to lower the temperature, only to have the temperature fall to under 200. Its a vicious cycle. My smokes generally are successful but I shouldn't have to keep going out and messing with the smoker every 10 minutes to get my meats to cook at the right temp. Overnight smokes are pretty much impossible unless I set an alarm every hour. I'm suspecting the wood chips are burning too fast/hot but I'm not sure whats normal and whats not. Are there other mods or suggestions I can do to the smoker to help stabilize the temperature? Or am I doing something wrong? Any and all help is really appreciated.
 
had a masterbuilt gasser and after many frustrating probs with trying to maintaining temps and trying to cold smoke bacon and having to hold temps my frustrations won and I gave away. eventually I turned smoker to high and back down to my desired temp.worked better. held temps better good for pulled pork but not for a cold smoke
 
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I have the masterbilt gashouse propane smoker. I took the stock chip pan and covered it with foil, about 3 layers worth. It kinda suspends the chunks above the bottom of the pan. Also put a gasket around the door. Smoked a turkey breast today and it maintained a steady 325 degrees. Have found that chunks just work better for me than chips.
 
I think several of us are saying the same thing different ways... The temp varies, not because your main gas burner or its gas consumption varies, but because your supplemental fuel source (the chips) are not being consumed at a steady rate.

It's kind of a surface-area-to-volume-ratio sort of thing. It's too easy for chips or pellets, being small, to flame up and cause your overall temp to spike. The bigger chunks are more likely to put out constant heat and smoke for the couple-to-a-few hours you'd like your smoker to go unattended. Think of them as a candle, not a match. You don't want them to flame up and burn too quick. Instead you want a fairly constant cross section that uniformly burns, steady as she goes. Chips, on the other hand, are more like a match than a candle.
 
Thank you all so much for your suggestions! I'm definitely switching to wood chunks and then going from there. I truly appreciate all your help and will update this weekend when I smoke some ribs!
 
And so how you set out a chunk is important. A triangular extruded chunk, placed point up, will burn more rapidly as the cross-section decreases from the bottom to the top, as it burns bottom to top That will cause your temperature to rise. But place it at 90 degrees, so it's sitting like a piece of pie on a plate, and it burns uniformly, from bottom to top, because each cross-sectional slice is equivalent.
 
If that’s the single door XL Masterbuilt. I have the same one.

My temperature swings disappeared once I switched to using a needle valve. I bought the bayou classic that has the needle valve in it. My temp will change maybe 5-10 degrees but I don’t get any wild swings.

I also got rid of the chip tray. I have a stainless steel grate that I place over the burner ring. I set an 8” cast iron skillet on top and burn wood chunks.

I also use the water pan that came with it but filled with sand and covered in foil. This acts as a heat sink and allows temps to recover quicker when opening the door, especially in the winter and colder temps.
 
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I have an update of sorts:

Have smoked ribs twice since I started the post. The first time, I used wood chunks and tried to leave the temp knob alone as much as possible when I reached the right temp. I was still seeing huge fluctuations (goal range 225-250. Saw temp spike to 300 without any knob movement. Tweaked the knob down and saw the temp drop to 215). Upon further investigation I saw that the cause of the spike is indeed the chunks burning up. Ribs still come out delicious anyways. More changes definitely need to be made

2nd attempt was last night. I decided to soak the chunks for about 1 hour before I started the smoker. I also purchased a cast iron grate. I placed the grate on top of the stock chip pan and then placed my cast iron skillet full of chunks on top of the grate. Still the same goal temp range. This time i only saw one spike up to 280 and was consistently seeing better temperature control. This really helped. I'm still gonna look into a needle valve, but it seems my problem is solved for now. Thanks to everyone for the suggestions. Now for the next step of nodding my smoker to keep the smoke from escaping through the door!
 
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I had a Masterbuilt propane smoker and sent away for a needle valve on the gas line just b4 the gas valve, I was trying to cut gas flow down enough to cold smoke bacon and what happened every 1/2 hr. the wind would blow out the flame. I frusratingly gave the smoker away.
 
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