What temperature should I put this cheap hair straightener at?

My GHD V hair straighteners broke(stopped heating up) and didn't have the money to get a another expensive GHD hair straightener.

So spent £20 on some cheap Remington 230 hair straighteners.
Has temperature gauge from 150-230 degrees C.

150 is doing absoletely nothing to my medium thickness hair,tried it on about 190 degrees.
Done something but still the ends are not dead straight.

Kinda scared putting it on 230 C incase my hair burns or looks really damaged,although got some cheap hair protectant spray(argan oil) in the cupboard which I could use.
But still scared, as normally don't go above 200-215 degrees C(with heat spray)

Oh and these straighteners STINK.

Might just be the new smell of the coating on the ceramic burning off,but doesn't smell nice at all.
Don't think it's my hair burning as not that kind of smell.

Smells like hot ceramic and the kind of smell when you light matches.

Figured it out in the end and put it on 230c, just hope it was the heat protective spray vapour causing steam, not my hair smoking....
Not tons of whatever that was, just a tiny wisp just after spraying.
Got a bit paranoid incase was burning my hair so put temperature to 210c approx.