MES Overheating

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Bobnrtp

Newbie
Original poster
Jun 10, 2024
10
4
I have an older MES model 20070910 I can set the temp to 200 and start heating. When it gets to 200 the Red LED turns off, but it continues to heat going up maybe 40 more degrees. I put my controller on another smoker and it works fine. Used the other controller on my smoker and it still overheats. Sent Masterbuilt a email and received a reply quickly. Sorry out of warranty. Anybody have any ideas what I can do to fix this without using a PID?
 
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Was this over temp discovered by using a reputable remote thermometer ?

The MES's are well known to be off by that much (40` more o less) from their set temp... So people use a remote thermometer and set the controller according to it instead of the MES's theremometer... Set your temps 40` lower than what you actually want it at...
 
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Was this over temp discovered by using a reputable remote thermometer ?

The MES's are well known to be off by that much (40` more o less) from their set temp... So people use a remote thermometer and set the controller according to it instead of the MES's theremometer... Set your temps 40` lower than what you actually want it at...
Just tried again with 2 Taylor and a TermoPro remote thermometers/ All three were close 1 or 2 degrees from each other. The MES control panel read about 11 degrees cooler. Again the Red LED light went off at 200 as I had it set, but temps went up to 300 and kept climbing. So I shut it down.
 
Sounds like it might possibly be a control board issue. The guy to consult about this would be tallbm tallbm , he's the resident MES guru.
 
Sounds like it might possibly be a control board issue. The guy to consult about this would be tallbm tallbm , he's the resident MES guru.
I pulled the cover off the control board and it looks like new. No hot spots or bulging components.
Sounds like it might possibly be a control board issue. The guy to consult about this would be tallbm tallbm , he's the resident MES guru.
 
Just tried again with 2 Taylor and a TermoPro remote thermometers/ All three were close 1 or 2 degrees from each other. The MES control panel read about 11 degrees cooler. Again the Red LED light went off at 200 as I had it set, but temps went up to 300 and kept climbing. So I shut it down.
Hi there and welcome!

The best explanation is that the relay (a switch) on the lower circuit board is stuck in the "on" position. The top controller cuts signal to that switch to tell it to go to the "off" position but if the switch is stuck in the "on" position, the switch will just keep letting the power flow to the heating element until the overheat safety switch cuts power off at like 305F degrees or so. Once it cools enough that switch will close back down and you will enter the same cycle becuase the relay is still suck in "on".

If you were more crafty than I with electrical components and could switch out that relay on that circuit board you would likely fix your situation. I think I've only ever seen 1-2 guys come through here that have done that but didn't really post about it much so not a lot of info to easily figure that out unless you deal with circuit boards and hardware like that a lot.

Your alternative is to do the simple rewire to bypass all the MES electronics and use a PID controller to run your smoker.

The Auber PID controllers run like $160 which would cause most people to think "that's almost as much as buying a new smoker" BUT, doing this is not turning your MES into an electric smoker that would cost over $1,000 brand new.
I always say its like turning a golf cart into a Ferrari! Your MES would look the same but perform a bajillion times better where it hits and holds the temps dead on or within 1-3 degrees.

Also when doing this rewire, if you switch out a few cheap wire connectors to ones that wont corrode away like the factory MES ones do, then you will have a smoker that you can keep running until a tornado hits it lol.

All of us MES-PID guys seem to wonder "why did I wait so long" after we've made the switch. I haven't heard anyone ever be disappointed with doing it :D

Here is the simple rewire guide for using being able to use your MES with a PID and avoid issues like this from now on :D

I hope this info helps, ask any questions you have.
 
Anybody have any ideas what I can do to fix this without using a PID?
You could add a fan with a speed controller to the same circuit.

Turn the smoker on and set the fan (blowing or pulling from the smoker) to a desired baseline speed for when the heating element is on (generally, a low speed). Then, when the heating element stops, the voltage drop caused by the heating element goes away, causing the fan speed to increase significantly. This mitigates the over-temp situation (less time spent above temp since the fan is acting harder during this time). You could choose to make this effect more pronounced by using an extension cord, if desired.

This will also work as a good test to see if the relay is "stuck" as tallbm tallbm hypothesized. If the red light goes off and the fan doesn't increase in speed, then it is indeed stuck. If not, it isn't.

[edit]
Oh, nevermind -- I just saw you say that it stayed at temp. Yeah, I'm guessing tallbm tallbm is right. The above approach might work if it overshoots and returns to 200, but not if it's staying at 300. That indeed sounds like a relay issue.
 
Last edited:
Hi there and welcome!

The best explanation is that the relay (a switch) on the lower circuit board is stuck in the "on" position. The top controller cuts signal to that switch to tell it to go to the "off" position but if the switch is stuck in the "on" position, the switch will just keep letting the power flow to the heating element until the overheat safety switch cuts power off at like 305F degrees or so. Once it cools enough that switch will close back down and you will enter the same cycle becuase the relay is still suck in "on".

If you were more crafty than I with electrical components and could switch out that relay on that circuit board you would likely fix your situation. I think I've only ever seen 1-2 guys come through here that have done that but didn't really post about it much so not a lot of info to easily figure that out unless you deal with circuit boards and hardware like that a lot.

Your alternative is to do the simple rewire to bypass all the MES electronics and use a PID controller to run your smoker.

The Auber PID controllers run like $160 which would cause most people to think "that's almost as much as buying a new smoker" BUT, doing this is not turning your MES into an electric smoker that would cost over $1,000 brand new.
I always say its like turning a golf cart into a Ferrari! Your MES would look the same but perform a bajillion times better where it hits and holds the temps dead on or within 1-3 degrees.

Also when doing this rewire, if you switch out a few cheap wire connectors to ones that wont corrode away like the factory MES ones do, then you will have a smoker that you can keep running until a tornado hits it lol.

All of us MES-PID guys seem to wonder "why did I wait so long" after we've made the switch. I haven't heard anyone ever be disappointed with doing it :D

Here is the simple rewire guide for using being able to use your MES with a PID and avoid issues like this from now on :D

I hope this info helps, ask any questions you have.

Tallbm, Thank you so much for the detailed expiration . The link to the MES rewire was also very helpful. Looks like something I can do easy enough. I have already removed the circuit board cover. So after they rewire the MES is plugged into the PID controller and the PID controller has its own Temperature probe?​

 

Tallbm, Thank you so much for the detailed expiration . The link to the MES rewire was also very helpful. Looks like something I can do easy enough. I have already removed the circuit board cover. So after they rewire the MES is plugged into the PID controller and the PID controller has its own Temperature probe?​

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


Yeah you already got to the circuit board so if you cut the ends off 4 wires and wire nut to make 2 whole wires then the rewire is done!

If you are lucky you have a unit that has big white plastic clips for the wires that come from the power cord (black smooth, white smooth wires) and another big white plastic clips for the wires that go to the heating element with the safety switch still in the mix (braided wires).
Those plastic clips will unhook from the wires that go to the board and you can hook the 2 different plastic clips together and boom rewire done with no cutting hahaha... again if you are lucky and have that version.

If not then 4 cuts and 2 wire nuts do the rewire.

Also yes, you are correct. The Auber PID will come with it's own temp probe.
The simplest thing is to drop it down the through the top MES vent and run it along the back wall and clip on the underside of the lowest smoker rack in the middle. This should give you the fastest response time. You just use the lowest rack first always when smoking and you will be getting temp readings at rack level :D

If you go the PID route I am pretty sure you will love how things work out for you :D
 
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I have an older MES model 20070910 I can set the temp to 200 and start heating. When it gets to 200 the Red LED turns off, but it continues to heat going up maybe 40 more degrees. I put my controller on another smoker and it works fine. Used the other controller on my smoker and it still overheats. Sent Masterbuilt a email and received a reply quickly. Sorry out of warranty. Anybody have any ideas what I can do to fix this without using a PID?
I've replaced the control panel, control board, heat probe, and element. The over runs continue.
 
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