MES40 2.5 loss of temperature control - any idea what the problem is?

[daveomak]

https://www.appliancefactoryparts.com/search/part/32683355/

The roll out switch is also available from the above....

 

[uncle eddie]

The repair is complete...heating up the smoker now to see how it does. If it does OK - ribs going on in 90 minutes.

I thought I would post the pictures for the repair as there were a few surprises. Total repair time was about 30 minutes. It would have been easier with 2 people, maybe save 5 minutes of repair time.

The before


Note the new bolts/nuts were much smaller than the old ones and they are all tiny. They slipped right through the MES40 housing case. I had to slightly drill out the holes on the new part using a 5/32" bit to make the old nuts/bolts work.

I also needed some penetrating oil to loosen the nuts, a pair of pliers and a standard sized Phillips screwdriver


I would venture to guess that MasterBuilt should spend a few more pennies on their connectors...maybe use high heat ones? This could be from when my MES40 got hot (315F or so)...but since the smoker can be set at 275F, I would venture to guess these connectors are not rated for the heat.


I pulled the melted plastic off and decided the actual wires/clips were OK. Since they are covered, I plan to leave it this way...unless it causes a problem.


All of the tools used. The directions provided by MasterBuilt were actually spot-on.


I was skeptical if this repair would fix the temperature control issue, but it seems to have done just that.

I have been running the smoker at 250F for 40 minutes now...and:

• It got to temp much faster than before the repair
• The temperature controller appears to be working again
• The temp is holding within 10 degrees (+/-) of 250F as checked with 2 separate calibrated thermometers - acceptable
• I do not smell burning electronics :)

Time to fill the AMNPS and get the St. Louis Style pork ribs on...

 

[uncle eddie]

Well that didn't last long. Smoker temp spiked to 315F. Doing the same temperature spikes again.

Calling Masterbuilt tomorrow

 

[Bearcarver]

Well that didn't last long. Smoker temp spiked to 315F. Doing the same temperature spikes again.

Calling Masterbuilt tomorrow

Yup---I still think it's your controller.
I had the same thing with a new one---It even made the Insulation make Crinkling noises.
They sent me a new controller----10 minutes later No more problem. Works perfectly ever since!

Bear

 

[tallbm]

Well that didn't last long. Smoker temp spiked to 315F. Doing the same temperature spikes again.

Calling Masterbuilt tomorrow

Yeah that make sense.
What they sent you was the safety cutoff switch not anything that is suppose to constantly regulate the temp.
Also you are right, they don't use hi temp connectors and after the controller the connectors on the switch you replaced and the heating element are usually the next things to go. They just corrode away very easily.