I'm not sure if IR Burners are supposed to be this way or not but after ripping the grill apart yesterday (stainless steel grills in 110 degree heat are HOT HOT HOT) i discovered that, unlike the other burner knobs, I need to push, turn, and hold in for a good 10 seconds. if i dont hold it in the gas wont flow.
the other knobs for the regular U burners i just push, turn, and release and the gas will still flow.
i dont know if this is by design or of there is something wrong with the valve.. either way its "working" and thats all that matters...
before i could only get the grill up to around 650 or so MAX temp.. yesterday i got it up to 700 after about 20 minutes of all burners on full blast.
My maverick ET-732 thermometer got up to around 650 before it began flashing HHH.