I own a MES Digital 30 Gen 1 which I love but yesterday was a nightmare with it. I set out to smoke my first Chuckie with a 235* set point and using the AMNPS filled with two rows of mesquite pellets. I also use the Maverick ET-733 to monitor Food and BBQ temps. Anyway, the smoker temp kept going up and hit 295* which is wild since the top temp limit for the MES is 275* but I saw 295* on my calibrated ET-733.
Some people complain that their AMNPS won't stay lit. I had the opposite problem yesterday with the pellets burning out after an hour, no matter how many times I refilled the AMNPS. Instead of TBS I saw large amounts of smoke coming out of the top vent. I tried a blend of wood pellets to try to slow down the burning but it didn't work. I even set the MES temp to 100* but it only went down to about 286*. This all happened over a 7-hour period.
Today, I cleaned both the temp sensor and the high limit switch inside the MES and put the Chuckie back in (it never reached the IT I was shooting for) and now the MES is back to normal. Still getting temp swings but that's normal. I have the MES temp set point at 245* and per the ET-733 the temp is swinging between 262 to 270. That was higher than I wanted so I just cut it back to 235* on the MES. The smoke out of the top vent is still more than TBS but some of the smoke coming out of the top vent is from grease and deposits inside the MES, not just from the wood pellets.
So, I learned something new about my MES and how to fix the problem. I'd advise all of you with Gen 1 MES smokers to clean at least two those components on the inside rear wall periodically since they both will get caked with deposits which can cause the problem I had yesterday.