RTDs and thermocouples are what measure the temperature of your grill. Each grill will have either an RTD or a thermocouple, depending on whether or not they have WiFIRE capabilities.. They are both very sensitive to both temperature and tampering, so you want to make sure you do not touch them while using the grill.
An RTD (Resistance Temperature Detector) is a 2" or 7" vertical rod inside the grill, used in non-WiFIRE enabled (AC) grills. The RTD is located inside the grill barrel, on the side with the hopper.
A thermocouple is a 1" metal rod inside the grill used in WiFIRE-enabled grills. The style of grill will dictate its location inside the grill. For Costco grills, the thermocouple will be vertically pointing up next to the bottom grill grate on the hopper grill side. For all other WiFIRE-enabled grills, the thermocouple will be sticking out of the barrel wall horizontally on the hopper side.
A new thermocouple will come with a protective covering, either orange plastic or cardboard. This must be removed before the grill is used. If you forgot to remove the orange plastic before seasoning your grill, and it has melted onto the thermocouple, please contact Customer Service for a replacement thermocouple.
If your RTD or thermocouple is bent, chipped or seemingly broken, test it to see if it is accurately reading the ambient grill temperature. If it is reading the ambient grill temperature correctly, there isn't a problem and you can continue grilling.
The best way to test your thermocouple is by comparing the ambient temperature of the grill to the external temperature.