this never happend before

[paul js]

I have used my WSM dozens of times now, frankly still surprised on how well it hits and maintains target temps. So my last 2 cooks , overnighters of a shoulder one time and brisket last night, I struggled to get temp. With all vents closed (including top) temp soared to 300. Took hours to get down. I always use MM, and water in the pan. I have not moved or made any modifications to the WSM in recent cooks. All parts fit snugly, I can find no source of air leak. Use ET73, tested with boling water and it is right on the mark. The only thing different in these last 2 cooks was both from newly purchased and opened Kingsford charcoals. Never heard of it but could this batch somehow be just more "volatile".

Any other ideas?

 

[Bryan S]

I know you checked but it sounds like an air leak to me.

 

[K Kruger]

Hmm. Was anything different about the size, quantity, placement or condition of the smokewood? (I'm thinking along Bryan's line but want to eliminate another variable.)

 

[Susan Z]

Maybe the whole top section was not seated in the bottom section tightly?

Bizarre!