It was plugged into the Pellet Boss... I will try the boiling water tonight when I get home. Thanks for the response...The MAK probes are very accurate (within 2 degrees), did you have it plugged in ti the Pellet Boss or your Mavrick? If your probe is that far off something is not right, you can check in boiling water at 212 degrees. Let us know what you find, if its faulty we will send you a new one.