MES40 Temperature Differential

Discussion in 'Electric Smokers' started by rcfire77, Sep 4, 2011.

  1. After having an 8# butt take way to long last weekend (over 20 hours) I decided to do some testing on my smoker to see how accurate the smoker's digital temperature indicator was. I have an MES40 with a 1200w heating element. It was approx. 85* outside and 65% humidity. The vent was wide open. I used my own digital probe thermometer, which has been tested using the ice water/boiling water test, and the unit's probe thermometer. I let the unit get up to each temperature, which it understandably always overshoots, then comes back down. I took all of the readings when the heating element came back on and the temperature hit the set temperature on the digital readout of the smoker. Here's the readings I got:

    Smoker Temp Readout                          My thermometer probe                Unit's Probe

    175*                              Lower Rack                    149*                                   148*

                                         Upper Rack                     157                                     155

    200                               Lower Rack                    184                                     188

                                         Upper Rack                     186                                     189

    225                               Lower Rack                     203                                    208

                                         Upper Rack                      209                                    214

    250                               Lower Rack                     222                                    228

                                         Upper Rack                      228                                    232

    275                               Lower Rack                     241                                    250

                                         Upper Rack                      251                                    259

    Quite a difference at all levels. What this means is that I can't really smoke anything that calls for a temperature of over 250* because the unit won't get there. Now that I have some baseline temperatures I will continue to do temp checks as I am actually smoking some food to see if they hold true over time. Any input or comments are welcome.
  2. smokinal

    smokinal Smoking Guru Staff Member Moderator OTBS Member ★ Lifetime Premier ★

    If I were you I would call Masterbuilt customer service & ask for a new controller.

    The new one will be off, but you need to be able to get the temp up to 275+.

    If your lucky you will get a controller that reads 275, and the actual chamber temp will be 300.
  3. jresurv

    jresurv Newbie

    That looks remarkably like the spreadsheet I just put together. Mine might be a hair better, but the highest reading I got anywhere in the box with the temp set at 275 was 256. When I called Masterbuilt they said a new controller wouldn't fix it, as it

    is a problem in the internal wiring. Since Ive only had it a week they said to return it so Sam's club and exchange it. If Sam's didn't like that idea to call them back and they would arrange a swap for a new cooker. 

    For people who have had this smoker for a while, does the thermostat seem to get better or worse over time? Also does the extra 15 or 20 degrees make a big difference on things like chicken? Sorry I am new to the whole electric thing. 

    Best case I guess is take it back and hopefully the new one isn't worse, or possibly even off the opposite direction.
  4. tjohnson

    tjohnson Smoking Guru Staff Member Moderator Insider OTBS Member SMF Premier Member

    You'll also have a difference in temps at opposite ends of each rack.

    The right rear corner of each rack has a "Hot Spot"

    The sensor for the controller is right in the hot spot.  This may be the reason that the rest of the uit does not get to the temp set on the controller.

    I can't think of anything that I would smoke above 250°, other than chicken, and that's just to get a crispy skin.

    If your pork butts are taking 20 hours, smoke for the first 5-6 hours in your MES, and finish in the oven.

    Check your racks, at both sides.

    Try pulling the chip pan about 1"-1 1/2" .

    The heat shield on the front of the chip pan does not allow for much heat to rise up the front of the smoker.  Pulling it out slightly, allows for some heat to rise up the front. 

    DO NOT Remove the chip pan!!

    The heat shield also protects the door.

    Last edited: Sep 29, 2011
  5. Remember that the temps in an electric smoker will cycle high/dead-on/low and repeat. If you were to chart your kitchen oven you'll see the same cycle. So, your temp reading will be dependent on when in the cycle you took the "snap shot". Gas and electric ovens (not single control non-thermostic gassers) all cycle through about 40-50 degrees.

    Don't agonize over this. Unless your controls and themometers are truly bad the meat doesn't care if the temp varies 20 degrees each side of "desired". The only time I worry is when I'm doing sausage and prefer the temp to be "low" so I sneak up on the internal 150!!
  6. jresurv

    jresurv Newbie

    So would it be your opinion it wouldn't be worth it to box it up and take it back to Sam's to try and get one that will go to 275?
  7. tjohnson

    tjohnson Smoking Guru Staff Member Moderator Insider OTBS Member SMF Premier Member

    There is a "Learning Curve" for every smoker you use.

    The next one may hit 275°, but will it maintain that temp?

    I have (3) MES 40's and they all have different characteristics for temp control. 

    My oldest MES is about almost 2 years old, and does not have the remote.  In-order to maintain 225°, I have to set it at about 200° or so.

    If I set the controller at 250°, temps inside my smoker were almost 300°!

    My 2nd MES 40 has the new remote, and I have set it at 215° to maintain 225° on the center racks.

    I just took my new one out of the box yesterday, and will do a few test runs to determine the accuracy of the controller.

    Yesterday, I set my 2nd MES 40 at 275°, and the element rarely turned off, even though middle racks showed 275°.

  8. bearcarver

    bearcarver Smoking Guru OTBS Member

    What Al said---You paid for a smoker that goes to 275˚------Mine is one like Al mentioned, & I love it.

    Next time you do a test like that. Check the readings of all of those probes & digital read-out on the way down too.

    When you're all the way up, set it at 100˚, and log in all the readings at various times on the way down.

    I did that, and they all got together & stayed the same all the way down, because the heating element was off, therefore there were no air currents in the smoker.

  9. jresurv

    jresurv Newbie


    Swapped for a new one at Sam's yesterday. Did another series of temperature tests today. You re right Todd the right rear of each grate is the hottest area. With a pretty good difference around the grates. I'm not trying to chase temperatures around the smoker, I just place 3 different probes at various places around the box and see if any of them ever make it  to 275. When I put a probe on the top shelf, right rear corner(right under the vent) it just  makes it  to 275, with a reading of about 263 tops in the middle of the middle rack. I was at 248-250 tops in the middle before I swapped.

    Thanks everybody for the help. Going over to buy the AMNPS now.

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