# Please Help - Masterbuilt Digital Electric Smoker Sensor stuck at 300 degrees F



## clarkkent1521 (Feb 20, 2021)

My Masterbuilt smoker control unit is always displaying 300 degrees. I took the control unit apart to inspect for any dirt or corrosion, but it still looks brand new. I cleaned the area around both the sensors inside and dried it off with hair dryer but that didn't help. I see screws on the inside to take out the sensors, but I don't see how to take the back panel off to remove the sensors. The back panel appears riveted on. I live in Florida and it's only 55 F, so it's not an outside temperature issue.


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## MJB05615 (Feb 20, 2021)

Welcome from Ga.
There are a few experts on here that I'm sure will chime in.  

 tallbm


 cmayna
  are a few, very helpful.
I'm no expert, but a few questions may shorten the time needed to go back and forth later.
The controller staying at 300, does that mean the temp inside the smoker is always at 300? or something else? Like not heating, too much heat, etc.
What model number is the smoker?  Have you looked online for troubleshooting in the meanwhile?
I've heard Masterbuilt's customer service is very slow to reply, but they have a facebook page that may be faster to help.  Sorry I couldn't be more help, but help will find you on here, that's for sure.


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## tallbm (Feb 20, 2021)

clarkkent1521 said:


> My Masterbuilt smoker control unit is always displaying 300 degrees. I took the control unit apart to inspect for any dirt or corrosion, but it still looks brand new. I cleaned the area around both the sensors inside and dried it off with hair dryer but that didn't help. I see screws on the inside to take out the sensors, but I don't see how to take the back panel off to remove the sensors. The back panel appears riveted on. I live in Florida and it's only 55 F, so it's not an outside temperature issue.



Hi there and welcome!

Often Masterbuilt digital eletric smokers (MES) can never even hit their stated max of 275F temperature so if you have one that actually hits 300F degrees I think you are in way better shape then most hahhaha.

The MES smokers are notorious for having temp probes that are just plane off.  As much as 15-30F degrees in some cases.  So all of us electric guys also get dual probe (or more probes) wireless digital thermometers and we test the thermometer probes to know how accurate they are.  They should read 212F degrees in boiling water or close to it.
Next we clip those probes at meat level on the rack in the smoker and that gives us the most accurate temp reading to go by.  You can then adjust your MES temp up or down according to your wireless thermometer rack readings.  I would suggest u get a thermometer with 4 -6 probes but 2 probes as the minimum, there are a number of good ones out there.

The screws you see the "button" looking sensor are fastening the safety rollout limit switch to the smoker.  That "button" sensor will cut power off  to the heating element for overtemp safety reasons, if it reads a smoker temp of 301F degrees.  
The other sensor that sticks out is the probe that the MES controller is using to read temp and is the one that is reporting 300F to the display.  
Knowing how notoriously bad all MES temp probes are (smoker and meat probes) I imagine you arent really hitting 300F, but only getting a multiprobe wireless thermometer will solve your mystery.

Don't worry.  We all get these multi probe wireless thermometers and yes they do cost a pretty penny BUT they are a necessity if you want to control your bbq smoking with precision and accuracy and to know what is really going on in your smoker.  It just sucks that Masterbuilt skimps so hard in this area BUT the rest of the physical smoker is where they really shine :)

I hope this info helps :)


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## clarkkent1521 (Feb 20, 2021)

It's reading the inside temp as 300 F, so the heating element never turns on because it thinks it's at 300. I have an Inkbird, but it's of no use because my smoker no longer heats up at all. How do I fix the probe sensor that's reading 300?


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## tallbm (Feb 20, 2021)

clarkkent1521 said:


> It's reading the inside temp as 300 F, so the heating element never turns on because it thinks it's at 300. I have an Inkbird, but it's of no use because my smoker no longer heats up at all. How do I fix the probe sensor that's reading 300?



Ah I understand better now.

The problem is likely that your connectors are failing at the safety rollout limit switch ( the button sensor), or the the switch itself has burned up.  It's Normally Closed so if it is ruined or a connector has burned up then u will never get power through it and onward to the heating element.

It seems you don't have a an access panel so you have 2 options:

 Drill out the rivets on the back of the smoker and fold up the back wall and you can get to the switch compartment.  You replace the rivets with self tapping sheet metal screws, i suggest the hex head ones.  I would cut an access panel for yourself at this point and cover with some piece of scrap sheet metal u can get form Home Depot or anywhere else.  Again use self tapping sheet metal screws to fasten this metal in place and tape over seams with flue tape or duct tape.


 You measure and gently cut a panel out of the back that will be big enough to give you access to the safety rollout limit switch compartment.  An 6 to 8 inch tall by 5 to 6 inch wide rectangle should get it done.  JUST DONT CUT DEEP or you may risk cutting wires.
You will need something like a Dremel rotary tool or an Oscillating cutting tool that can cut metal to cut it. You want to barely go through the metal.
Again use a piece of sheet metal and self taping metal screws and tape to make a panel so u can get to the compartment again.  This stupid switch is delicate can fail on you a number of times... I know from experience.

So, once you get to the compartment and you can assess the issue here are the parts that will get the job done:

Here are high temp connectors that wont corrode on you.  The Masterbulit ones are pure trash.  You may want to also replace the connectors at the heating element with these because those may fail soon as well:

Here are replacement switches BUY THESE EXACT ONES!!! There are 2 different styles and the other style physically wont work so these will get the job done and you want extras if your current switch has failed.  They are a little delicate and can melt down on you if you wiggle the tabs at the back of the switch in any form or fashion:


Finally, until you get the parts in you can simply disconnect the 2 wire ends from the safety rollout limit switch and splice the ends together and wrap with electrical tape so they are sure not to touch any metal.  Your smoker will work but will not have a safety switch in the mix so this is your call and be safe (I do this when mine fails and I need to get through a smoke because luck has that it usually fails mid smoke hahaha)


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## Steve H (Feb 21, 2021)

The roll out switch could cause the display to be stuck on 300?


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## clarkkent1521 (Feb 21, 2021)

tallbm said:


> Ah I understand better now.
> 
> The problem is likely that your connectors are failing at the safety rollout limit switch ( the button sensor), or the the switch itself has burned up.  It's Normally Closed so if it is ruined or a connector has burned up then u will never get power through it and onward to the heating element.
> 
> ...


 
Thank you. I guess I'm going to try these things. Hopefully it solves the problem.


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## tallbm (Feb 21, 2021)

Steve H said:


> The roll out switch could cause the display to be stuck on 300?


[EDIT] Looks like I was extra confused.  Clark is reporting that the controller is showing 300F all the time.


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## clarkkent1521 (Feb 21, 2021)

tallbm said:


> Ah I understand better now.
> 
> The problem is likely that your connectors are failing at the safety rollout limit switch ( the button sensor), or the the switch itself has burned up.  It's Normally Closed so if it is ruined or a connector has burned up then u will never get power through it and onward to the heating element.
> 
> ...



I removed the button sensor and taped the two wires together. It's still reading 300 degrees or getting ERR1 code. Also, all the quick disconnect tabs still look brand new. No corrosion, no dirt, no grease.


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## tallbm (Feb 21, 2021)

Ok maybe I misunderstood more than I thought.
If it is displaying 300 then your controller seems to be messed up since you say the heating element isnt even on.

Sounds like you have a bad controller or bad circuit board at the bottom.  The top controller is often a failure point.  The circuit board underneath is not often the issue.

Well you can try and get another controller from Masterbuilt but it seems their customer service is nonexistent at the moment.   
Your other option would be to buy something like an Auber PID controller and do the simple rewire and rock the PID controller.  It would make your smoker 10X better then any brand new smoker Masterbuilt ever produced but it does cost like $150 for the controller :(


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## clarkkent1521 (Feb 26, 2021)

tallbm said:


> Ok maybe I misunderstood more than I thought.
> If it is displaying 300 then your controller seems to be messed up since you say the heating element isnt even on.
> 
> Sounds like you have a bad controller or bad circuit board at the bottom.  The top controller is often a failure point.  The circuit board underneath is not often the issue.
> ...



Masterbuilt customer service said I need to replace the bottom circuit board. I found them online for $75. I'm not willing to spend $75 to maybe fix this.


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## river100 (Feb 27, 2021)

clarkkent1521 said:


> Masterbuilt customer service said I need to replace the bottom circuit board. I found them online for $75. I'm not willing to spend $75 to maybe fix this.
> 
> You could look into replacing the master Built controller with a PID controller hardest part is weatherproofing it, which just me getting the right box.


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## tallbm (Feb 27, 2021)

clarkkent1521 said:


> Masterbuilt customer service said I need to replace the bottom circuit board. I found them online for $75. I'm not willing to spend $75 to maybe fix this.



That sucks.
You have the option of doing the simple rewire and using an Auber PID controller.  The cost will be $150 for the PID controller HOWEVER your smoker will easily be 10X better performing than anything Masterbuilt makes brand new.

I always tell people the best electric smoker is an MES40 you get on Facebook or Craigslist.org for like $40-50, rewire, and slap a PID controller onto!!!

This one with the "multi purpose" sensor will do the job.





						Multi Purpose Controller [WS-1510ELPM] - $159.95 : Auber Instruments, Inc., Temperature control solutions for home and industry
					

Auber Instruments, Inc. Multi Purpose Controller [WS-1510ELPM] - The WS-1510ELPM is a versatile temperature controller to have in your home. It can be used for various applications such as Sous Vide cooking, controlling an electric smoker, making yogurt, dough proofing, controlling the...



					www.auberins.com
				




You can turn this smoker into a beast!  With quality high temp connectors replacing the crappy ones that Masterbuilt uses and rewired using this Auber PID you can keep that smoker running through anything short of a cannon blast! :)


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## campfirestu (Mar 5, 2021)

This post about the Auber seems like a great solution. I did not know they had them with a built-in relay. It even comes with a thermocouple. To hook it into the smoker could take some wiring skills to bypass the existing controller. Maybe a friend who is familiar with wiring could help. It would be good to have the existing over-temperature safety switch (if there is one on the smoker) wired in line with the heater element if possible.


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## tallbm (Mar 5, 2021)

campfirestu said:


> This post about the Auber seems like a great solution. I did not know they had them with a built-in relay. It even comes with a thermocouple. To hook it into the smoker could take some wiring skills to bypass the existing controller. Maybe a friend who is familiar with wiring could help. It would be good to have the existing over-temperature safety switch (if there is one on the smoker) wired in line with the heater element if possible.



Well friend here is a post with lots of details and pictures on how to do the simple MES rewire to use with an Auber PID :)





						MES Rewire Simple Guide - No Back Removal Needed!!!
					

Lately I've seen a number of posts about guys wanting to rewire their MES.  I had wanted to post a quick and simple guide for those out there that are curious or those that simply need to rewire but need a little assistance.  Well here goes.  Disclaimer:  When messing with electrical equipment...




					www.smokingmeatforums.com
				




In short you cut the ends off 4 wires and splice/wire nut to make 2 wires and then the MES plug will work with an Auber PID :D

Enjoy the info!!!


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## campfirestu (Mar 6, 2021)

Great info - I don't own a MES but I could have used this controller on my oven conversion rather than my Omron E5 and external SSR. The nice thing about it is the enclosure the Auber comes with. It's best to utilize the thermal overtemp limit switch if your unit is equipped with one.


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## tallbm (Mar 6, 2021)

campfirestu said:


> Great info - I don't own a MES but I could have used this controller on my oven conversion rather than my Omron E5 and external SSR. The nice thing about it is the enclosure the Auber comes with. It's best to utilize the thermal overtemp limit switch if your unit is equipped with one.



Finding proper enclosures is a major pain so I agree lol.


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## Bearcarver (Mar 13, 2021)

JackmaElen said:


> Hello Guys!
> 
> *Here are some tips to enhance Masterbuilt Temperature:*
> 
> ...




Tip # 3 would be better to say:
Never close the top vent of an MES while smoking. You need the air flowing through, and there is already plenty of humidity in an MES, which is why we don't add water to the water pan.  You can close the top vent after smoking is done, to hold the finished meat until time to eat. Also close top vent when not in use to keep bugs out.

Bear


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## clarkkent1521 (Jun 5, 2021)

tallbm said:


> Hi there and welcome!
> 
> Often Masterbuilt digital eletric smokers (MES) can never even hit their stated max of 275F temperature so if you have one that actually hits 300F degrees I think you are in way better shape then most hahhaha.
> 
> ...


It was the bottom power circuit board. After a couple months Masterbuilt sent me a new circuit board which I wasn't expecting. Replaced it and all is well.


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## Bearcarver (Jun 5, 2021)

clarkkent1521 said:


> It was the bottom power circuit board. After a couple months Masterbuilt sent me a new circuit board which I wasn't expecting. Replaced it and all is well.




That's Great that You're good to go.
Shame it took a couple months though.
Now you can show us what you can do with it, with Pics!!

Bear


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