So, you have conducted all of the research that you have deemed necessary and have come to the conclusion that the specific grill thermometer you are after is accurate. Then, after you use it, you notice that it is wildly inaccurate and you are left scratching your head to why this is occurring. Well, not all hope is lost as there could be some common issues that are happening. For one, which will get touched on in a bit, the probe may simply need to be calibrated. If the issue is deeper than this, though, it is possible that the main unit and wireless receiver need to be re-synchronized (which will also be discussed).
If neither of these solutions remedies the issue, it is possible that your probe is damaged and this can be caused by excess heat or moisture (if it is not waterproof).