On Sun, 12 Nov 2017 01:55:21 GMT, Johnny B Good
wrote:

snip

Obviously, the oil heater section will draw the power selected by the
power selector switch until the thermostat cuts out (assuming the stat
was set for an achievable temperature).

snip

I'm guessing your 'obviously' above is assumed? ;-)

The OP could also have assumed that the power drawn would relate
directly to the switch settings and the thermostat but it seems it
does not.

Cheers, T i m