Greetings all, new to the forum. I just had this problem with my Original Bradley Smoker, purchased in July 2017. I wanted to put this here in the event someone searches with the same issue. I found similar issues, but not this exact one with a resolution. It wasn't the heater element.
The symptoms were:
Today (5th use) it wouldn't go over 160 degrees. Before today, it would get up to 225, but it would take a while, and when I would open the door for whatever, it would take 45 minutes or more to get back up to temp. Being new, I didn't know this wasn't spec.
I went a-googling and found where others were asking for solutions. I saw the extra element mod, and a couple others. Someone suggested to check the plug into the back of the box. That piqued my interest. Mine was working to a degree, so this didn't seem significant, but then I realized I've seen my power connector loose, and even checked it today when I was trying to get the heat up.
I realized the connection being loose wasn't good, so I got a pair of needle nose pliers and bent the conductors so the female plug would seat better and didn't move.
I turned it on, and bam, within a few minutes it was up to 240 degrees. I would have found it earlier if the element wasn't warming at all, and it didn't occur to me at first that the loose fitting would restrict the voltage, instead of not letting any through.
Been smoking for a while with a Chargriller and SFB. I decided to make life a little easier.