On 19/10/2010 17:16, Tabby wrote:

How is a non-flammable metal/sand heating element in an enclosed steel
space going to catch fire?


Presumably the element is at the bottom of the oil container, so the
heat is carried away by rising hot oil.

As the oil level drops it will cease to circulate, the element now being
near the top of the remaining oil.

The oil nearest the element will now receive the entire element output.

Do not leave it unattended!

Andy