Is there a difference between anschalten and einschalten?
If I turn on the TV, oven, heat, start the car etc., can either verb be used?
Generally both words einschalten and anschalten mean the same thing. Duden defines them as
durch Betätigen eines Schalters in Betrieb setzen
Thus you can ein- and anschalten the following things:
While I would use einschalten rather than anschalten in most cases, Google shows a lot of hits for anschalten though. I assume a regional difference in respect to frequency. Others may elaborate on this thought.
In case of heating, however, I'd use einschalten and anschalten when activating the heating system in autumn (i.e. it was completely shut down during summer); and anmachen (colloquial version of einschalten and anschalten, respectively), aufdrehen or hochdrehen (drehen defines the sort of action/movement you do when you turn on a radiator) when it's cold and I want the radiator to work.
In the end, it's similar to turn on/off and switch on/off in English. You can interchange them quite often as well.
The ngram on the following four forms shows a superior usage of
einschalten and a slight augmentation concerning
anschalten since the turn of the millenium
eingeschaltet - blue
angeschaltet - red
einschalten - green
anschalten - orange
Although both terms usually mean to turn things on, "Einschalten" can also be used for persons or departments when they are brought into something. Like:
Er hat einen Rechtsanwalt eingeschaltet.
Die Polizei hat sich eingeschaltet.
Das Amt für Migration schaltet sich ein.
You could not use anschalten for this purpose.
If you want to turn someone on, you couldn't use neither einschalten nor anschalten, but anmachen.
While I also consider anschalten and einschalten as mostly synonymous (no difference in your examples), I'd like to add the following
Anschalten has a (rarely used) additional meaning, which I would consider as technical term and which relates to the equally rarely used substantive Anschaltung:
This means, to
add some device to an already existing wiring
and has a very similar meaning to anschließen (connect).
Examples (unfortunately for Anschaltung only, since internet search for anschalten apparently yields only false positives):