I bought a MES 40 back in January and used a few times with some success. Today I decided to do some pulled pork. Started it at 9am this morning and it's is now currently in the oven at 8pm at night to finish heating. It seems no matter what I did today I couldn't get a consistent temp. I watched it go from mid 230's to low 200's repeatedly. I will say it was cold and outside temps were around 35-36 most the day and I run with the vent wide open. The Probe is also way off. It was reading 191 when I pulled the pork, my Digital Themo says it was 165ish. I know I'm going to call
Masterbuilt tomorrow to see what can be done before the warranty expires. Anything I can look for in advance?
It would be a rare occasion if your MES smoker sensor was within 5* of the correct temp. Some of it is because of where the sensor is. If you had your meat next to the sensor, it might be closer. Most guys, including myself just ignore the MES temp, and go by what their Maverick Digital wireless, or another wireless therm' says.
As for the meat probe accuracy, mine is usually pretty good, but I still don't rely on it. I go by my Maverick ET-732 meat probe, and even then I usually double check some things, like my Prime Ribs, with my
Thermapen, before pulling.
Also the MES controls, when set at 200*, will turn the element on at 198*-199*, then shut off at 200*, but the heat will coast upward for awhile. It depends on ambient air as to how far it coasts. If it's cold out, it won't coast upward so much, but if it's warm out it could coast 5*, 10*, or even more.
Also by the same token, when that temp drops down to 198*, and the element comes on it doesn't instantly warm up in there. It will coast down for awhile, until the heater catches up. On warm days it might only drop a few degrees before it starts rising, but on a cold day, it may drop 10 or more degrees, before it starts picking up in temperature.
Refrigerators are similar, as my meat fridge holds meat IT at 37*-38*, but the air in that fridge cycles between about 29* and 44*.
I hope you understand my gibberish---It's kinda hard to explain.
Bear