Not necessarily. Depending on how the device was wired, the motor could still be getting 110V in a European setting. Still wouldn’t heat very well.
Regarding the electrical codes, any dwelling built to the existing code at the time of construction is automatically grandfathered. However, if you hire an electrician to change the vanity lights, he’s obligated to bring the circuit he’s working on up to code at that time.
Crafter_man here’s how it looks. There’s a small round object that looks like the head of a screw on the handle of the dryer. On the handle at the 11:00 position of the screw it says 256V, at about 7:00 it says 125V. When I looked at it this morning the screw head was positioned 11:00 and 5:00 so that it looked like it was pointing to the 256V. I got a screwdriver and moved it so that it’s point to 7:00 and 1:00, 125V.
I didn’t notice any appreciable difference in the performance of the dryer though.
The etching on the side of the dryer says 256V/125V AC, 1900 W, 60 Hz (I had to get out the reading glasses for this part, it’s hell getting old)
I’m OK with making sure the lights are off in the other bathroom, just don’t want to risk electrocuting my daughter or myself and/or starting a fire. It doesn’t sound like I’m in imminent danger of these things. Of course next time I buy light bulbs for the bathrooms, I’m going with the 25W bulbs.
It would appear that it is “just now blowing the breaker” because it was always on the verge of doing so and when you changed to 40 watt light bulbs the current increased just enough to trip the breaker.