My 3.5 year old MES40 just broke

Discussion in 'Electric Smokers' started by uncle eddie, Aug 18, 2017.

  1. uncle eddie

    uncle eddie Smoking Fanatic SMF Premier Member

    My MES40 is about 3.5 years old and for my last smoke, the smoke chamber temperature went wonky.  

    The push-button control panel stopped working right a couple of months ago - I could only use the minus button to lower the smoke chamber temp and the cook time - but it seemed to be fine using blue-tooth.

    For my last smoke - When I set the temp to 275F, the chamber made it to 220F +/-.  When I set it to 225F, the chamber was closer to 190F +/-.  

    I just received a new control panel from Masterbuilt...lets hope that works.  BTW - they did not charge me for the control panel so I am thinking this must be an existing problem that was pretty wide spread.
  2. cmayna

    cmayna Master of the Pit OTBS Member SMF Premier Member


    At worst case if the new controller doesn't resolve the issue, you can always look into controlling the smoker with a PID.
  3. uncle eddie

    uncle eddie Smoking Fanatic SMF Premier Member

    Repaired!  Sort of.

    I finally put in my new control panel and meat probe.  It took about 35 minutes.

    I did bring home a calibrated thermometer from our testing lab to compare the meat probe vs. calibrated thermometer.
    • Crushed ice water - calibrated and MES meat probe = Calibrated read 32.2F, meat probe 32F
    • Boiling water (as best I could manage) - calibrated and MES meat probe = Calibrated read 203.2F, meat probe 204F
    • Both were tracking well at intermediate temperatures when I put them in the smoke exhaust.  
    I now have a lot of confidence in my new meat probe.

    NEW PROBLEM - the actual temp in the MES black box runs about 25F to 30F hotter than what the MES40 is set at - as verified by my newly calibrated meat probe and the calibrated thermometer from our lab at work.  

    I will call Masterbuilt tomorrow and see if I need a new sensor or controller - but probably both.
  4. redoctobyr

    redoctobyr Smoke Blower

    Good news on the repairs!

    Where are you measuring the temperature? Right next to the smoker's sensor?
  5. dr k

    dr k Master of the Pit

    Too bad that vertical smokers don't have a tethered chamber probe to be placed next to food. Or the manufacturer tell us to put your food on the what ever level because that's where the controller sensor is on the back wall. Like the meat probe they tether. I think they want people to smoke on the second from the bottom rack where their sensor is at the back wall before going to another rack. Set the controller to 275*F. Figure out the rack level temp and drop the controller temp doesn't matter. It's only as accurate as your after market calibrated therm tells you. John Mac.........whatever Dadgum saying he says with his dadgum filled smoker maxed to 275*F during his demos. It's Chinese crap. You have to work with it to make it brilliant. Now that I did all my dadgum mods I'll be dadgum to ever need a dadgum other smoker.
  6. tallbm

    tallbm Master of the Pit

    I think your new problem may actually be a bit of a blessing.

    I could never get my MES40 to hit 275F and it was always about 30-35F degrees low.  Going high you can always deal with but not being able to hit a temp is something you cannot work around.

    I have since rewired and use a PID controller and I hit every/any temp I set with few hiccups :)
  7. uncle eddie

    uncle eddie Smoking Fanatic SMF Premier Member

    I was measuring in the chimney to check my calibrated thermometer against the meat probe.  But I also tend to do most of my cooking on the top 2 racks.  25F-30F is a huge difference though - I could understand 5F or 10F degrees.

    Now that I know the meat probe is accurate, I will place it next to the temperature sensor and test it that way.

    I was also thinking that I like the idea of it running a little hot.  Being able to get the MES40 up to 300F is something that I can see as long as it still can hold 225F.  I may just calibrate the temp. sensor and live with it and simply make a calibration table.  I would have 3 columns - set temperature, sensor level temp, chimney level temp.   

    I will post my results...
    I think I arrived at the same conclusion...glad you posted this though - sometimes I am a bit slow haha
    Last edited: Aug 24, 2017
  8. tallbm

    tallbm Master of the Pit

    No problem, I'm glad the info helped :)

    I have tried a ton of things to regulate temp within my MES40.  This includes installing a convection fan, flipping the heating element, messing with a duct for the vent, heat baffles, a PID controller, etc. and I have come to the conclusion that you simply cannot get past the nature of the design.

    Basically each rack will have a different temp.  Even on the same rack you will have different temperatures from left, center, right positions.  

    I have been able to get quite a bit of consistency keeping temps the same or within the same ranges between racks as well as along the left, center, right positions of a single rack.

    I have never been able to get things even between two racks or even across a single rack.

    Every so often I even create situations where the smoker probe is blocked by meat or a pan and does not read temps properly.  This is why I use 3 smoker probes so I can get the BEST range of readings I possibly can and when necessary I make adjustments to my set temp.  For example the other day I set my foil pan and my smoker probe in a position where the smoker probe was reading 60 degrees lower then the other two probes.  Once I noticed this situation I simply changed my set temp to hold according to what the backup probes were reading.  Simple work around.

    I have one final trick up my sleeve.  I have a Birch wood board cut and ready to act as a shelf that helps trap heat underneath it.  Smoke and air will be able to rise around it BUT my hope is that I can slow it enough to help trap heat under it.  This way when I only use the bottom rack or bottom two racks that I can put this wooden shelf in to try and trap heat and keep it more consistent below the shelf. 

    The idea is that I have less wasted space to heat... I just need to get some whole chickens to do a test run with this idea.  This is the last mod I can think of that I can do to try and help the temp consistency even more hahahaha.

    Anyhow, best of luck and multi probe thermometers are your friend with the MES :)
  9. uncle eddie

    uncle eddie Smoking Fanatic SMF Premier Member

    I checked the set temp, top shelf, and 3rd shelf temp on my MES40 today.

    With the vent wide open, the set temp and the smoker temp at the top and 3rd shelf were within 5-6F degrees of the set temp.  Of course the smoker temp drifts a bit - about +/- 5F before the element turns on/off and there is a little temperature change lag in the calibrated meat probe...but I am happy with the results.

    It looks like the new control panel did the trick.

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