I just got one of the Weber Summit series grills that has the smoker box. I am having issues using it - despite soaking the wood chips, one of two things happens: either the chips catch fire or they do not smolder at all. I just cannot get the right heat. Does anyone have experience with this grill? It has a separate burner directly under the box. Usually I try to start the smoker burner on about medium-high while the rest of the grill heats up (about 15 minutes) and then when I put food on, turn the smoker burner to low. But a lot of times, I check on the food a few minutes later to find the chips burning. I've also tried just turning the smoker burner off once the food goes on, but then I don't get much smoke. Any advice?