Preheat your smoker to 275°F (135°C). If you're using the Billows™ BBQ control fan with your RFX GATEWAY, set the fan temp for 275°F (135°C), otherwise, set your high-temp alarm for 300°F (149°C) your low-temp alarm for 250°F (121°C) and monitor your smoker with the included air probe to make sure it stays in the proper range.
Rinse your corned beef and pat it dry.
Insert your RFX MEAT probe into the corned beef and place it in the smoker. Set the high-temp alarm for 160°F (71°C).
When the alarm sounds, place your beef in a pan and add boiling water to come 1/3 of the way up the side of the meat.
Wrap the pan tightly in foil, insert the probe through the foil into the meat, and reset your high-temp alarm for the meat to 203°F (95°C).
Cook the corned beef in the pan until the alarm sounds. Verify that the meat has reached 203°F (95°C) throughout by spot-checking with your Thermapen ONE. Remove the corned beef from the water pan and, if it needs further tenderizing, wrap it tightly in two layers of foil, then wrap it in a few towels and stash it to rest in a cooler for an hour or two. But if the tenderness feels right, it's time to eat.
Slice thinly and serve!