MES 30 wont get to temp!

[husker3in4]

My saga continues. I have a Gen 1 (one of them) MES that I had for maybe or 5 years. It died after maybe 18 months, so I changed the element with no luck, then changed the little round thermostat with no luck. So it sat in storage for 3 years until I had a buddy help me test the parts. Turns out it was the little round thermostat. The one I replaced must have been bad because as soon as we bypassed it, the smoker cranked right on up to 250. So I ordered new ones, and got them in a couple of days ago. I just plugged the wires into it and left it dangling out of the smoker, just to test if the one on was good. Again, the smoker fired up and ran at 250 for a couple of hours. Rejoice!!

So last night, I screwed it into the smoker, put the back plate back on (which is a huge pain in the rear!) and fired up the smoker to 275 to burn off mold and other gunk that grew inside for the past 3 years. I checked it a couple hours later and it was at 81 degrees and would not get warmer. What gives? The thermostat is supposed to go up to 150 c (302f) and it only seemed to work when it was outside of the unit, the ambient temp of the garage was probably 40 degrees a couple of nights ago when I tested it, but last night when it was actually detecting temp inside the smoker it wouldnt let it heat past 81 f degrees.

Im beyond frustrated!

Here is the thermostat I ordered and tested fine outside of the unit, but something is not letting the unit heat past 81 when its inside the unit. If you click the image it will take you to the amazon page I bought it from with its specs.

 

[old sarge]

There comes a time when it becomes necessary to take a piece of gear off life support and move on. I would get a new smoker, a better smoker.

 

[husker3in4]

Id be lying if that thought didnt run through my mind already. But thats another $180 and still trying to stop the bleeding from getting $725 stolen by the USCIS. I actually have another smoker, but this one has been my favorite. I am wondring if I should just bridge the 2 wires together and just bypass this thermostat, its more of a safety thing.

 

[Bearcarver]

Id be lying if that thought didnt run through my mind already. But thats another $180 and still trying to stop the bleeding from getting $725 stolen by the USCIS. I actually have another smoker, but this one has been my favorite. I am wondring if I should just bridge the 2 wires together and just bypass this thermostat, its more of a safety thing.

I would check with tallbm on this forum. It could be something simple, and he's one of the guys who understands that kind of thing.


Bear

 

[husker3in4]

I clicked your link for tallbm but I dont see a way to private message him?

 

[Bearcarver]

I clicked your link for tallbm but I dont see a way to private message him?

I alerted him of this Thread.
However on this new forum platform, it's not called a "PM".
You have to click on "Start a Conversation".

Bear

 

[Heath Phillips]

My guess would be that when you install the temp sensor into the unit, something is touching metal inside and grounding it out. My first suspect would be the blade connectors on the sensor. Also could be a chafed wire.

 

[husker3in4]

well when I tested it, those same wires were plugged into it, so I dont think it is a wire issue. But you might have a point about it being grounded out. the screws that were originally holding the thermostat to he body are too small now, cause everytime you unscrew it and screw it back in (at least 10 times at this point), the hole gets a little bit bigger and I have to use a larger screw. It is possible that the new screw head may be touching the thermostat on the inside of the unit, is that what you mean? When I get home I can take a pic of it.

 

[Heath Phillips]

Yeah. Maybe the screws are touching the wire connectors inside the wall.

 

[tallbm]

So last night, I screwed it into the smoker, put the back plate back on (which is a huge pain in the rear!) and fired up the smoker to 275 to burn off mold and other gunk that grew inside for the past 3 years. I checked it a couple hours later and it was at 81 degrees and would not get warmer. What gives? The thermostat is supposed to go up to 150 c (302f) and it only seemed to work when it was outside of the unit, the ambient temp of the garage was probably 40 degrees a couple of nights ago when I tested it, but last night when it was actually detecting temp inside the smoker it wouldnt let it heat past 81 f degrees.

Im beyond frustrated!

Here is the thermostat I ordered and tested fine outside of the unit, but something is not letting the unit heat past 81 when its inside the unit. If you click the image it will take you to the amazon page I bought it from with its specs.

View attachment 353263

Hi husker.
I have seen something like this in the past in my own personal experience... a couple of times lol.

The metal tabs on those rollout limit switches are a little delicate. If you managed to bend or wiggle the metal tab that is fastened to the plastic piece of the rollout switch (see the following image) then it causes resistance and the plastic melts and burns up which leads to more resistance until the whole component begins to fail.

In my situation I switched to using Hi-Temp Steel electrical connectors so they wouldn't corrode (the MES stock ones are junk). Well they Hi-Temp ones are so snug that it took some manly force to get them on snug which in turn loosened the tab that is fastened to the rollout switch.
After a couple of usages I noticed that my smoker was only going to certain temps and then cutting off even though the temps were like 250F then 200F then 175F, etc.
What was happening is that the switch itself was heating up due to the electrical resistance of the wiggling tab and it was cutting the power.

I also ran into the case where I tried to put the connectors on more delicately without forcing them all the way down. Same issue occurred because the connector was a little loose and wiggly on the tab which caused resistance and heat up and the switch to burn up the same way hahaha.


In short I think this is what is happening to you.

Unfortunately you didn't cut a panel out for your rollout limit switch so you must take the back off again to check it out :( I cut a panel into mine using a dremel and a metal cutting wheel just because of this. I have replaced at least 3 limit switches before I got everything right hahaha. Below you can see my home made panel with a piece of scrap aluminum I got from a buddy (right side of smoker with aluminum tape around the panel as a seal. Any sheet metal should do as a cover.

Try not to get frustrated, I am positive we can get you up and running but you will have to pull the back off again to see what the switch is doing because I have a sneaky suspicion you are having the same problems I did OR you are right and your bigger screws are causing some grounding and overheating.

Let me know if this all makes some sense :)

 

[husker3in4]

Yep, that makes perfect sense. Although, I dont think Im caused any wiggle like you describe, not yet anyway. The connectors on the wires are fairly loose fitting on the thermostat, but they were the same way when I tested it outside of the body and they worked fine. Ive attached a picture of the rather large screws that are holding it into the body:

They do look like they are touching it, at least on the right side. Do you think if I used some skinny bolts with a nut on either side that would work better?

 

[SonnyE]

I'm sitting on the same bench with Old Sarge. Stop beating a dead horse.
That said, There are only so many things that can go wrong. And it's a process of elimination.

UNPLUG THE UNIT WHEN WORKING ON IT! Sorry, it must be said.

It the element reads with an Ohm Meter, it's likely good.
If the Over temperature device (commonly called a Thermo-disc, or Snap-disc device) is closed when reading it with an Ohm Meter, it may be good.
This is a safety device to avoid burning down your house. You could bypass it for testing, but never walk away with the smoker plugged in in that state. If a fire insurance investigator finds out you burned down your house by bypassing a safety device you are void, Vic.
Also, substituting a part that looks the same, may not be the same. I admittedly do not know the specification (temperature range) of the OEM part. But 300* F should be sufficient for a smoke box.

81 degrees is suspect to me. The fact that there is heat occurring leads me to believe the disc and element are likely functioning. And makes me look towards the actual temperature control.

There is a lot more to it than that, a failing connection can heat up and cause an open. Then after cooling for an undetermined amount of time, become conductive again, making one think it is a different problem.
So not everything is straight forward, sometimes.
But to save costs, it is best to find the problem and correct that.

Only 18 months of joy before having troubles is rather disappointing.
But I'd probably replace it. And likely with something different.

 

[tallbm]

Yep, that makes perfect sense. Although, I dont think Im caused any wiggle like you describe, not yet anyway. The connectors on the wires are fairly loose fitting on the thermostat, but they were the same way when I tested it outside of the body and they worked fine. Ive attached a picture of the rather large screws that are holding it into the body:

They do look like they are touching it, at least on the right side. Do you think if I used some skinny bolts with a nut on either side that would work better?

It may work better, that would be closer to the original config.
At the moment we are flying a little blind until you cut a panel or pull the back off the smoker again. I suggest you pull the back off and measure before cutting a panel lol.

Once you take a look at the rollout limit switch look for any burning, melting, or discoloration. Even on the rubber sheet thing that fits over it. If you see some then you know that is your issue.
Also look at the wires that go in and out of the holes that lead to the limit switch area. Often they become frayed and you may be grounding out.

So in short you gotta look at it to see what is going on and pics would be helpful so we can see it too :)

 

[jp61]

From your description of what's going on, it's possible that one or both wires connected to the switch are faulty or there's a loose connection on either end of one or both wires. Your original part may still be good. Moving the wires around while troubleshooting could have been making or breaking connections?

 

[jp61]

Yep, that makes perfect sense. Although, I dont think Im caused any wiggle like you describe, not yet anyway. The connectors on the wires are fairly loose fitting on the thermostat, but they were the same way when I tested it outside of the body and they worked fine. Ive attached a picture of the rather large screws that are holding it into the body:

View attachment 353280

They do look like they are touching it, at least on the right side. Do you think if I used some skinny bolts with a nut on either side that would work better?

The screws touching is not the problem. If they were touching one of the terminals that would be a problem, but you would know it from the tripped circuit breaker. Loose connections are for sure part of the problem and possibly the wiring as I mentioned above.

 

[husker3in4]

If the problem is loose wires, should I just try to crimp down the connectors onto the thermostat posts? I should be able to mess with it tonight. One thing I DO know, is that Im not putting the back on it again until I get it working thru several tests. At that point I will probably cut out an opening for it like tallbm did. Would a sawsall cut thru that backing?

 

[tallbm]

If the problem is loose wires, should I just try to crimp down the connectors onto the thermostat posts? I should be able to mess with it tonight. One thing I DO know, is that Im not putting the back on it again until I get it working thru several tests. At that point I will probably cut out an opening for it like tallbm did. Would a sawsall cut thru that backing?

I think you could crimp down the connectors onto the tab but again the switch tabs can be a little delicate at the point where they are fastened to the rollout switch (plastic with some ring-rivet thing to hold the tab in place). Just take your time and try not to make the tabs wiggle. You may see that the switch is already burning up and in that case you will want to replace it. This has been my experience for sure. Soldering would be a good approach too if it doesn't cause the plastic part of the switch to melt.

A sawsall would cut through the metal backing no problem but is likely to be overkill and little awkward to maneuver lol. The back sheet metal isn't very thick sheet metal. The important thing is to get the hole cut in there to save yourself some grief in the future. If you have the Gen 2 model backing design then that lip and rib design is a PAIN to put the back on again. I did it with the Gen 2 I rewired and gave away as a gift (got it for $40 on craigslist ).

Let us know what you find and pictures are always super helpful :)

 

[jp61]

If the problem is loose wires, should I just try to crimp down the connectors onto the thermostat posts? I should be able to mess with it tonight. One thing I DO know, is that Im not putting the back on it again until I get it working thru several tests. At that point I will probably cut out an opening for it like tallbm did. Would a sawsall cut thru that backing?

I don't know what's wrong with your smoker but loose connections with electricity is never good.
Just make sure that all connections you can get to are clean, tight and wires are in good shape.

It sure would be nice to have wiring diagrams to all these different brands, models and years of electric smokers and all in one place. Would be much easier to try and help someone in need.

 

[husker3in4]

Ok guys, so I did some testing last night. I took the back off (again, ugh) and removed the screws holding the thermostat switch device in place, and the screws holding the little protective box in place. I checked to make sure the posts were not loose, and the connections while not super tight, werent very loose either. The round thermostat itself was still in the hole in the smoker so I plugged it in and fired it up. Checked it 15 mins later and it was still at 36 degrees, not heating up.

So then I removed it from the hole and let it sit outside the smoker, plugged it in and turned it on. Checked it 15 mins later and smelled something burning. Uh oh. The smoker is at 233 of 275 I set it to and it was almost there, thats great! Bad news is the wire that goes from the thermostat to the heating element post was burning at the connection point on the heating element. My buddy had put a piece of duct tape over both heating element posts and it had burned thru it (thats what I smelled) and burned part of the wire closest to the heating element post. I took a pic and quickly unplugged it.

So the good news is the thermostat still appears to be good. The bad news is the wire coming from it and going to the heating element burned for reason. 2 questions: did it burn because it was a replaced wire that didnt look as thick? and why would the thermostat allow it to heat up while its laying outside of the smoker, but not while its inside the smoker?

I have some pics for reference:

Here you can see the little glow on the left heating element post, that is where it was burning the wire and thru the duct tape:

I had to lay the thermostat outside of the smoker to get it to heat up, here is a pic of where it was:

A closeup of the heating element posts, the left one is clearly burned, I cant tell if the right one was also burning:

 

[tallbm]

Well looks like you found the culprit, the wire and/or connection to the heating element.

To answer your question I don't think the rollout limit switch (you refer to it as the thermostat) being outside really allowed it to heat up, I think it was more of a jostling of wires in general or something like that.
Just be sure to look real hard at the rollout limit switch and if you find any burning, melting, or heat discoloration on the plastic, the tabs, or connectors then you know you have an issue there as well.

Three things you need to check in this case before just re-splicing the burning up red wire.

1. Is it a high enough gauge wire. The MES uses 14-16 gauge wire so you need that or better (12, or 10 gauge would be better). I would suggest trying to keep with the same level of wiring as the rest of the MES for electrical consistency to not introduce differences.
2. The connectors you are using for the wires and heating element are not Hi Temp. The Hi Temp stainless steel ones will hold up A LOT better than regular connectors. MES uses cheap regular connectors at the heating element and rollout limit switch connections and they are the most commonly failing areas in the wiring setup.
3. Check for frayed wires, repair, and or wrap/insulate them. I'm not sure if the wire that is failing was always in that shape or not but in the last image you posted I can definitely see fraying on the ground wire and on the black braided wire going to the heating element compartment. If you have LOOSE connections/wiring you will get overheating and burning up. If you have frayed wires touching metal you will/can ground out or burn up depending on what it is touching.

So in short, repair the wire with an appropriate hi temp 14-16 AWG one.
I suggest using Hi Temp stainless steel connectors at least for the heating element:
or

A little high temp insulated shrink wrap to go over your connectors wouldn't hurt either:

Repair and protect any frayed wires that may contact metal.

Good job finding the immediate problem area Let us know how you decide to go with the repairs, and best of luck on the repairs :)