How long have you run it?
If you think you might have got a bit of oil on the heating coils when you oiled the motor, it is probably fine and you just need to let it burn off the oil that got in to the wrong place. Is it a burning oil smell or a burning electrical smell? It might be the motor burning up if you have reassembled it wrong or if there is a short in the motor winding.
I hope you are testing this using a RCD-protected power point? I have a "death preventer box" I made up myself - an extension cord has a plug with built -in RCD ("Safety Switch") and the outlet is a box that has a resettable circuit breaker 10 amps before the outlet socket. Any fault should trip either the breaker (overload) or safety switch (Earth Leakage device, RCD.) The plug's RCD is more sensitive than the one in the house breaker board, so it trips first - saves the nuisance of resetting clocks etc that were on the same circuit.
I assume "hero mode" is a typo, what do you mean? If fan stops when you switch it to heat, you have a problem - faulty switch, or a short in the heater element that uses so much current that the voltage drops and the heater slows down - this should trip a breaker, though.