Originally Posted by ekjohns
Ive test my thermometer and its accurate. It seems like the liquid boils then rises to the surface then gets pushed over as more boiling water is pushed up. As it gets pushed over from the main heat source it cools until it cycles back to the element.
That's exactly what's happening. Vessels will have a flow caused by the rising/falling of heating/cooling liquids. Hot and cool spots are typical, unless you re-circulate.