MES 40" Temperature Issues with Auber PID & Mailbox Mod

Discussion in 'Electric Smokers' started by straightshot, Jan 14, 2016.

  1. straightshot

    straightshot Newbie

    Hi all,

    I have a MES 40" that I purchased from Amazon two years ago and have had off-and-on problems with the control panel dying.  Last summer my wife and I moved and I had just replaced the control unit and once we moved into the new home, second use on the new panel, it wouldn't accept any button input for the time setting to start the smoker.  I called Masterbuilt and they charged me another $60 for another control unit which resolved the issue.  My temps were spiking all over the place so I decided on replacing it with an Auber 1800watt dual-probe PID.  I did a lot of research on the mod before purchasing and saw most people went with the 1200 or 1800watt depending on available funds.  While I was waiting on the PID to arrive, I decided to do the mailbox mod (looks easier in the pictures!) which was a success and made a huge difference in the cooked food.

    Fast forward two weeks.  I installed the PID by bypassing the MES control panel (disconnected it from the access panel in the back and sealed the existing connections).  I installed a 14AWG power cord directly wired to the burner element and fired it up without any issues.  I know the Auber has an auto-tune so I let it run its first cycle and to ensure nothing caught on fire. :)  The temp outside was cold (probably 30) with a lot of wind and the temp got up to around 234 max during the auto-tune process in an hour time frame.  I decided to turn off the program feature from the PID and lock it in at my desired smoke temp.  225 will take on average 30-40 minutes to hit this target and I smoked chicken last weekend and set the PID at 250 and it never made it to that temp.  I re-did the auto-tune process (without any smoke) on another cold/rainy day and let it run for well over 5 hours to ensure it completed this time.  I tried smoking a pork loin tonight at 260  (wanted to do a higher temp 2 hr smoke and finish in oven) and I never got the smoker above 235 degrees again, this was letting the smoker run over an hour and the temp outside is 52 degrees right now.

    My question is, is it the heating element that is the problem, the PID itself, or a combo of both?  I know for a fact the stock control panel could get the unit up to 275 on the CP readout, but it was off by about 5-6 degrees.  I also ensured the elbows going into the smoker are sealed around the entry points, I did upgrade the exhaust dampener by installing two 3" elbows.   Does anyone have any advice on what I can check before I call Auber and Masterbuilt ? Obviously the warranty is voided on the smoker so I am thinking of upgrading to a Smoking-IT 3D model and just giving up on this Masterbuilt.

    Thanks for the help and love the forums! 
  2. I have an Auber PID on my MES 30 analog. From what you are saying, it sounds to me like your auto-tune went awry. I found that the default settings in the Auber actually worked fairly well. There was definitely room for improvement, but temps were +/- 3 deg out of the box. If I were you, I would start over with the PID. Reset it to the factory default settings. There is a function to do this. On an afternoon that is not too cold, put a few bricks or something else to simulate a load in the smoker and set a nominal temp such as 220 deg and fire it up and let it get up to temp. Once the set temp is stable, say 30 min at temp, start the auto-tune and let it run to completion. It should not take more than an hour or so.

    The purpose of the auto-tune is for the PID to learn the characteristics of your particular smoker while at a nominal temp. Once it has learned this it will be more accurate, however once you get near the extremes of set temps like 20 deg over ambient or max smoker temp, the less accurate the PID becomes. Lastly, experiment with probe placement. Usually in the center of the smoker near the rear is the best spot. Hope this helps.
  3. straightshot

    straightshot Newbie

    Afternoon Haulin,

    Thanks for taking the time to explain everything, it sounds like I did botch up the auto-tune.  The only reason I attempted it in the first place is because I couldn't get the smoker up to the correct temp I wanted, not due to an offset in temp.  

    Since I did this on a cold day with no load simulation, I will take you advice until it is warmer out and give it a shot.  My prob is attached to my middle grate towards the center, I will also try moving it back a bit.

    Have a good weekend.
  4. walta

    walta Smoke Blower

    When you had it set for 260 and the cabinet temperature never got over 235.

    1 Was your PID cycling the heater on and off?

    2 Was the PID probe completely inside the smoker cabinet?

    3 Was the PID probe touching anything but air?

    4 Have you put the tip of the probe in boiling water and see if the display read 212°

    Does Your PID have 2 probes?

  5. straightshot

    straightshot Newbie


    1.) PID was cycling on and off, yes

    2.) Temp probe for cabinet was all the way in, unit sealed other than the exhaust being open

    3.) PID probe not touching 

    4.) I did not but I tested it again a thermopen and a maverick wireless unit, all within 1-2 degrees of each other

    5.) Mine has the 2 probes and I verified I am using the correct one for the cabinet and other for food.  Interesting enough, the food probe reads higher in the same spot as the cabinet one.
  6. walta

    walta Smoke Blower

    From your answers it seems your new PID is faulty.

    I would do one more test before I sent it back.

    Try plugging toaster oven into your PID with the probe inside and see if works. If not ask for a new PID.

  7. From what I see, the PID isn't the issue. It seems to me an auto-tune was started while trying to achieve a maximum set temp which was never achieved causing the auto-tune to not complete properly. A reset to factory and an auto-tune at a nominal temp with a load should get things running properly. There are too many factors involved in not reaching max temp to blame it all on the PID. Ambient temp, wind, vents, air leaks, etc. all play a big part. JMHO.
  8. Hi, I don't have a MES40 but I do run a Auber on my MES30. It has never been auto tuned. It ran to my likes ( + or - 2 degrees) right out of the box. I like the other posters who recommend that you bring it back to the factory default Think that is a good starting point. on the factory settings I think your heating issues will disappear. The reason it takes a little longer to  heat up is because of the way a PID works.It sends Full current for part of the heating cycle then it reduces progressively till it  hits the set point. If I want it to heat faster I set the set point 30 degrees higher than I want to cook at and when I hits the cooking temp I want  I reset the cooking temp to it. I might be wrong but I think it works faster at least it does for me.   Jted
  9. straightshot

    straightshot Newbie

    Hi all,

    Sorry for the late follow up, had a family emergency and it has been super cold/raining here in GA past two weeks.  I ended up doing a factory reset on the PID this morning and threw a 8lb pork butt in there early this morning.  Temps were 27 degrees but after the reset, the PID pretty much nailed the temp +- 2 degrees as mentioned above.  I have it programmed at 235 and it is sitting at 234 right now after several hours of smoking.   I think I am going to forgo doing an autotune on the unit until I see some higher temps outside.

    I will post some pics tonight of the finished product. :)

    Thank you to everyone for their help!
  10. dr k

    dr k Master of the Pit

    Did you leave the guts in the Mes (chip tray, housing etc.?) Or is it just the element open? Just wondered if the PID is more consistent without metal around the element. Or if the guts are out with using the Mes controller if the temp swings are are noticeably smaller with the mailbox mod.

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