Seasoning new Model #2 Shoots up to 520+ degrees in 30 min

[drew]

I followed the directions to the letter. 4 small chunks of wood in the wood box, line the top of the box and the floor of the box with foil remove all the shelves and set it to 250 for 3-4 hours.

I hooked up my FireBoard ambient sensor and walked away for about 30 minutes.

https://share.fireboard.io/F3752F

I came back to find the temp at 520 degrees and climbing, panicked and turned it down to 100 where it leveled off at 300. I noticed the control light turned off and discovered it doesn't turn back on unless I turn it all the way to 250.

I let it cool off a bit and have determined it was simply turning off the element and the power light when the temp was over where the knob was set. So it seems the thermostat is working.

My big concern is it seems like the thermostat is bypassed when the knob is turned to 250. My expectation is if I set it to 250, it should shut the element down to keep it around that temp. Is my thermostat or controller defective?

I was really hoping to smoke a pork shoulder this weekend, and I may still give it a shot but I'm having trouble setting my mind at ease with regards to the thermostat not doing it's job. Anyone else run into this?

 

[barelfly]

So, with nothing in the unit to help with a heat sync, and being that you have an analog, it turns up quite a bit to get to temp. My time on this board, I don’t remember anyone saying they got a reading of 520+ though. That’s pretty dang hot.

Maybe some of the others that are more familiar with the analog functionality will help with this, I don’t have much to add since I have the digital model. But, I do know there are some swings, especially at the start to get to temp.

 

[drew]

I'm starting to think it was some kind of fluke. You can see the thermo temp is sitting at 250 now, the knob is at 225. I just walked out and turned it to 250 again, I want to see if it keeps going up above 300 like before..

When it was really hot before I opened the box thinking maybe the wood was on fire, it was smoking like crazy but not on fire that I could tell.

 

[old sarge]

A couple of things to look at.  Where did you have the probe for the fireboard located?  Near the built in box probe or down near the element? As mentioned by barelfly with nothing in the smoker to absorb the heat - intercept the heat between element and probe, you could get a high reading.

Your controller is of the capillary type. The following information is copied from the included link.  It explains how this works:
"In Capillary thermostats temperature sensor consists of probe, capillary tube, diaphragms and expansion medium. When the sensor is heated, the liquid medium heats up and expands. The expansion of the medium increases in the closed-circuit system.
The pressure increase is converted into displacement in the diaphragm. This displacement, also called travel, actuates a snap-action switch, which opens or closes the contacts in the electric circuit."  (http://www.thermowatt.com/en/category/capillary-thermostat-electric-ovens#application%5B%5D=158&application%5B%5D=163)

Do you have an instant read infrared thermometer?  This will not "prove" anything but take a reading of the element itself after it has been on 15 or 20 minutes.  You will see that it is far hotter than what you set the temp for.  This is normal.

If you have a modern HVAC system in your house that is serviced regularly in spring and fall, you might notice the technician taking readings at the registers. Ask him/her what the reading are versus what the thermostat is set for.  You will find the air coming out will be far colder or hotter than what the set temp is. That is the only way to comfortably condition the air for the entire room/home.

If you are concerned, for your first cook, I suggest pork ribs. They are usually done between 4 and 5 hours at 225 degrees. I would just prep them and some them at 225 and check at the 3 1/2 or 4 hour mark for doneness.How much pull back of the meat from the bone? Can you slide a tooth pick into the meat at the bone? You will have to do your own judging.  With your fireboard and proper probe placement relative to the built in probe, you should see not more than a 20 -30 degree temp swing high and low of the set temp as the unit cycles on and off. That would be typical. The final result is that the temp pretty much averages out to your set temp. And the food is good.

 

[drew]

Thanks for the reply Sarge, what you said makes sense. I think I just have some new user jitters.

I ran it for a few more hours last night set to 250* and it worked about like I expected. I really think you're spot on about the issue being temp probe placement. Since I was seasoning with no racks in it I couldn't hook my sensor to the rack. I had it hanging in the middle of the box. I'm betting it fell down onto the firebox/heating element. I can't confirm it because I pulled up on the sensor wire when I was messing with it but this makes the most sense to me.

 

[Lonzinomaker]

I got  a new #1 recently and for the seasoning smoke it went up to 375, the wood did combust because it was all ash. I was also concerned that the temp shouldn't have gotten that high. But I then put a big rock and some water in and ran it again. Temp still got high. My #3 did the same thing when new.
But I remembered some threads where other people had high temps during seasoning smokes so I wasn't to worried. Went ahead and smoked a turkey breast.  Controller worked and temps stayed in acceptable ranges.  Subsequent smokes have gotten a little tighter on temp swings. 
I don't know for sure, but suspect some analog controllers need a break in to work correctly.