Diagnosis
The ERR code is a generic fault. On the OG701, it usually means the main control board detected a problem with a critical component at startup.
How to Fix It
Unplug the grill from the wall outlet. Wait 60 seconds. Plug it directly back into a dedicated 15-amp outlet. Do not use an extension cord. Turn the grill on. If ERR returns, the issue is likely a faulty temperature probe or a shorted heating element.
If That Didn't Work
The internal fuse on the control board may have blown. This requires removing the rear access panel to check the 5-amp glass fuse. Replace it only with an identical 5-amp, 250-volt fuse.
Heads Up
Do not ignore ERR codes. Repeated attempts to start with a fault can damage the control board permanently. This is not a user-serviceable error reset.