MES40 Heat Sensor Malfunction?

[jcam222]

I have had my unit for about 6 weeks now and have used it at least a couple of times a week or more. Today I had in 5 racks of ribs and a bunch of chicken breast. I was running at 250 since the ribs went in at 11am. Around 2 I added chicken breast. I went out a half hour later and noticed the smoker said it was at 200, it struggled to increase and was about 30 minutes later it said 225! I cranked up the smoker to 275 to see what would happen.  I then noticed that the built in probe that had hung outside the smoker all day (using better thermo) said 190 degrees!!

Finally using my other thermo it said the smoker was in the 300 range!! I did reboot the smoker with a two minute unplug to no avail. 

Have any of you had this kind of failure on the unit?? I am at a loss as to what happened. 

 

[tallbm]

Don't trust the MES probes, they are notorious for being off.  Always use a reliable after market probe to get a more accurrate temp.

Second, the MES airflow is definitely NOT even.  One area will be off from the next, even inches apart.  One rack will definitely no be the same temp as another rack, etc, etc.  It's just the nature of the beast.

Third, if your smoker is struggling to come up to temp you may be getting drippings on the burner so check for that... it happens with mine and mine is even more susceptable than most because I removed the whole chip loader/cover contraption.

If you load lowest rack first and use your smoker temp probe there you will have the best luck on that wrack.  Put lower/slower cooking items in the next closest rack levels.

If the roll out limit switch gets to 301F the smoker should kill power temporarily to the heating element as a safety measure and then allow power back on once it has cooled enough.

I wouldn't freak if the MES temporarily hits 300F, at least you can get 275F or a little higher in spots.  My MES couldn't even hit 275F anywhere so I rewired and added a HeaterMeter PID controller along with a few other mods.  I solved that problem real quick :)

Best of luck and I hope this info helps :)

 

[jcam222]

I am really thinking some sort of sensor or controller malfunction. When the probe is hanging outside with an ambient temp of 87 and it's reporting 200+ that beyond inaccurate. The inside cabinet temp was close to 300 and climbing based on my own thermometer yet it was still in heating mode, I did confirm it was still heating as the element was bright orange. The digital display in the smoker and via Bluetooth app reported 213. Adding to that I turned it on this morning and the probe is immediately reading 290!! Lol

 

[tallbm]

I am really thinking some sort of sensor or controller malfunction. When the probe is hanging outside with an ambient temp of 87 and it's reporting 200+ that beyond inaccurate. The inside cabinet temp was close to 300 and climbing based on my own thermometer yet it was still in heating mode, I did confirm it was still heating as the element was bright orange. The digital display in the smoker and via Bluetooth app reported 213. Adding to that I turned it on this morning and the probe is immediately reading 290!! Lol

Yeah your smoker probe sounds like it is shot.

It appears you either replace the smoker probe or you can rewire the smoker and go with a PID controller.  You'll lose bluetooh and remote functionality if you replace the controller with a normal PID controller like those at Auber.  I went hardcore and did a HeaterMeter PID controller build with my MES rewire.  It is a quite a bit more involved but if you have the skill and the knowledge it will give you a much better smoker and you can even control it from your phone if you want to go full blown internet capable setup.

If I were in your shoes I simply wanted to get back up and running I would get a replacement smoker probe from masterbuilt,  

Just know that the quality will still suck but it beats the guessing game you would have if you replaced it with a reliable probe and then found out that the Masterbuilt controller uses some unknown programming logic to interpret or convert the actual reading according to their programmed controller behavior for their smoker.  It's a definite possibility.

Best of luck and let us know what happens as we could all learn from it :)

 

[jcam222]

 
Yeah your smoker probe sounds like it is shot.

It appears you either replace the smoker probe or you can rewire the smoker and go with a PID controller.  You'll lose bluetooh and remote functionality if you replace the controller with a normal PID controller like those at Auber.  I went hardcore and did a HeaterMeter PID controller build with my MES rewire.  It is a quite a bit more involved but if you have the skill and the knowledge it will give you a much better smoker and you can even control it from your phone if you want to go full blown internet capable setup.

If I were in your shoes I simply wanted to get back up and running I would get a replacement smoker probe from masterbuilt,  

Just know that the quality will still suck but it beats the guessing game you would have if you replaced it with a reliable probe and then found out that the Masterbuilt controller uses some unknown programming logic to interpret or convert the actual reading according to their programmed controller behavior for their smoker.  It's a definite possibility.

Best of luck and let us know what happens as we could all learn from it :)

I really don't care a whole lot about the probe as I have a nice two probe unit to use. What concerns me more is I am relatively sure the temp monitor for the unit is also bad. I think its not sensing the heat inside correctly. Yesterday when I found it at like 190 it took almost an hour for it to report 220, I put my own probe inside to measure smoker temp and it was over 300!! 

I've done about 10 other smokes in it and the temp remained nice and consistent even through a 14 hour pork butt.

 

[sweenner]

Does anyone know if it is the probe or control board that is the culprit? I have thought about replacing the chamber probe, but not knowing what type it is, I didn't want to just blindly throw one in.

 

[jcam222]

I will be calling Masterbuilt support tomorrow. I'll post up what they tell me. I have read of the probe going bad quite often. I have not been able to find a lot on my issue which also seems to involve temp control for the unit.

 

[jcam222]

Support was closed for the holidays until yesterday. They are sending replacement probe, replacement main control and some lower board for chamber heat sensing as well. Considering the unit is 6 weeks old I pushed to cut cord or return for new unit considering this a lemon. They refused despite my best attempt to describe how frustrating it was to spend the little free time I have rebuilding their smoker The only bright spot was that they did tell me the 90 day warranties have been extended to 1 year. She said they did not update documentation with that and only tell customers who call. Pretty crappy. It's further pretty telling that the manual itself comes with the instructions to replace the controller, probe and power supply baked in. Tells me failure is frequent. I love this thing when working but I wouldn't rush out and buy another for a second smoker.

 

[jcam222]

I received the replacement controller, thermometer and power supply a couple of days ago. I have to say I am still pretty ticked off that at 5 weeks old they made me replace all of these parts as opposed to cut the cord for a replacement unit. The time I spent fixing it could have been a hell of a lot more relaxing lol. 

That said I replaced the controller and probe first. I have run a short test doing some T bones and seemed to hold temp fine, probe was as accurate as expected. I am about 6 hours into smoking 40 lbs. of pork butt , knock on wood, so far so good. 

Ill just keep the power supply handy for the future. 

 

[sweenner]

Thanks for the update jcam. How labor intensive was it replacing the parts? And where are these pictures man...you can't tease like that.

 

[tallbm]

 
I received the replacement controller, thermometer and power supply a couple of days ago. I have to say I am still pretty ticked off that at 5 weeks old they made me replace all of these parts as opposed to cut the cord for a replacement unit. The time I spent fixing it could have been a hell of a lot more relaxing lol. 

That said I replaced the controller and probe first. I have run a short test doing some T bones and seemed to hold temp fine, probe was as accurate as expected. I am about 6 hours into smoking 40 lbs. of pork butt , knock on wood, so far so good. 

Ill just keep the power supply handy for the future. 

Well with what you have done you probably now know the inner workings of your MES quite well.  If you ever decide to bypass the stock MES controller for a 3rd party PID controller you can see it won't be rocket science to rewire the smoker to bypass the current MES controller and circuitry.

I hope everything turns out well on your smoke :)