MES 30 won't heat

[HickoryBoy]

Model - MB25071217
Smoker won't heat up. It's not that it gets up to a certain temperature but not all the way. It doesn't heat up at all.
I've replaced the element. I've check the wires on the circuit board. The red temp light on the controller comes on.
So last night, when checking the circuit board on the bottom of the unit... I disconnected all wires/connectors and reconnected. Plugged in the unit and it flipped the breaker - 20amp. Reset the breaker. Checked the connectors again. Tried the unit again. It came on and let me set the temp and time. Never started to heat up. It did trip the breaker one more time, but not any more. One of connectors, the black at the "top" was pretty rusted. I cleaned it up pretty good, but still won't heat.
I checked the voltage at the back, behind the element and I only get ~34 volts after checking the circuit board. I was getting 120v last week. I also get ~34 at the red side of the black relay on the circuit board. Pictures for reference.

 

[jaxgatorz]

tallbm the one to ask. He should see this.

 

[cmayna]

Many of us have learned how to eliminate the entire circuitry of the smoker by using an Auber PID controller. I attached a power cord directly to my MES40 heating element. The other end of the cord is plugged into the Auber controller. Never looked back.

 

[mosparky]

I think you still have some connector issues. You may have to totally replace the rusted connector at the relay and clean the brass terminal on the relay itself REAL good. Also check connectors at the element and roll-out switch. All are prone to failure. If you have the ability, soldering the wires/connectors to their respective terminals works well too.

 

[HickoryBoy]

I think you still have some connector issues. You may have to totally replace the rusted connector at the relay and clean the brass terminal on the relay itself REAL good. Also check connectors at the element and roll-out switch. All are prone to failure. If you have the ability, soldering the wires/connectors to their respective

Thanks so much for the reply. Much appreciated. I believe you could be right.
Can the rusted connector be replaced or does the whole relay get replaced? It appears like the connector is "melded" into the relay.
At the element, the connectors actually look great, like new.
Is the roll-out switch the one that's on the inside, about half way up? There's not a way to access that unless I cut a hole out of the back, which I guess I could do. Is that what I'd have to do?
Thanks again.

 

[chopsaw]

The picture of the bottom access looks like it has gotten water in it . I would imagine if the outside of the relay and transformer look like that , the inside does too .

Yes to access the limit switch you have to cut a hole in the back . There's threads on that here somewhere .

 

[HickoryBoy]

Th

The picture of the bottom access looks like it has gotten water in it . I would imagine if the outside of the relay and transformer look like that , the inside does too .

Yes to access the limit switch you have to cut a hole in the back . There's threads on that here somewhere .

Thanks.
To replace that connector… can I replace only the connector, or the relay, or the whole circuit board?

 

[mosparky]

Finding replacement parts is near impossible from what I gather from multiple post here of people trying to source them. You could have a real good time trying to find a relay that matches the footprint of the one they used, but it might could be done.
If it were me, I'd secure all the connections one way or another and see where that gets you. If that fails to get it up and running, I'd start looking at PID controllers. Easier to find than control boards for an MES and far more reliable. They can be had cheaper than a New smoker of almost any brand and will perform as well as or better than many top dollar electric smokers.
But first lets take the easy/cheap approach and get those connections secure and see what you got. Careful measurement will tell you where to cut out for the safety switch and most any plate of sheet metal and a little silicon can be used to fashion a cover for the hole you cut to get to it.
The Limit /safety switch is on the left side as you look in the door ( NOT IN THE MIDDLE ) and about the size of a nickle.

 

[chopsaw]

To replace that connector… can I replace only the connector, or the relay, or the whole circuit board?

Mosparky has you covered in post #8 .
Police up the connections , cut the back open and check the limit switch .
Keep us posted .

 

[tallbm]

Th

Thanks.
To replace that connector… can I replace only the connector, or the relay, or the whole circuit board?

Hi there and welcome!

Guys are giving you really great info.

Here are some hi temp connectors that fit your wires and the tabs they plug onto.

https://www.amazon.com/Supco-T1111-Disconnect-Temperature-Female/dp/B0071NC5NO/ref=sr_1_1?crid=CCI0DUK4DKT&keywords=supco+t1111&qid=1681954462&sprefix=supco+t1111%2Caps%2C197&sr=8-1

You can replace the connectors to start with and it is a good idea to do so because Masterbuilt uses cheap crappy ones that want to rust and corrode away super fast.

As the guys stated, you will have to cut a panel into the back of your smoker to get to the safety switch. You will want to do this for sure because this is a major failure point where the connectors or the cheap plastic switch rust/corrode or melt down.
Here is THE EXACT ceramic replacement switch that shouldn't melt so fast if you need one, and yeah a 5 pack is nice to have because these parts are cheapo and can wear out anytime lol. Don't try and get a different switch because there are 2 different styles that looks the same but one style absolutely will not work!

uxcell A13092400ux0093 5 Piece NC Ceramic Temperature Switch Thermostat 155 Degree Celsius KSD301 Gold Tone Terminal: Industrial Basic Switches: Amazon.com: Industrial & Scientific

uxcell A13092400ux0093 5 Piece NC Ceramic Temperature Switch Thermostat 155 Degree Celsius KSD301 Gold Tone Terminal: Industrial Basic Switches: Amazon.com: Industrial & Scientific

www.amazon.com

If you are in a pinch and the safety switch is the problem, you can remove the safety switch and wire nut together the wires ends that were connected to the switch.
WARNING: you have now removed the safety switch so do this at your own discretion and accept responsibility for what may happen when removing a safety device :D (have to put that in here lol)

So with the easy things fixed (connectors and maybe even a safety switch) your smoker may be back up and running.


If your smoker does not work after those simple fixes, then your lower circuit board or your top controller is busted. My guess with your pics is that the lower circuit board is busted and that the relay is likely rusted in place not allowing power to go to the heating element.

Your option at this point is to do a simple rewire job (or new cord directly to heating element) and use a PID controller if you want to have an amazing smoker that performs like a beast and holds dead on to what temp you enter in.
Or you can go more analogue and get a rheostat dial controller for things like an oven and just turn a dial and let it do what it does and manually fiddle to get your temps or make your own notches. It will work but I like to know what is going on AND I like the tight control of a PID controller so I can do sauasge, bacon, jerky, fish, etc. without fear of spiking temps ruining the food and melting out fat (MES currently works on average temp where it overshoots high and then drops low giving you an average temp vs dead on temp).

I hope this info helps and ask any questions you have. This is a very solvable situation with your MES :)