A level which you are able to choose on a device can be called a "setting". We also use the verb "set" to describe putting something on a certain level:

I have the chicken set on low, so it'll cook like that for an hour or so.

When you move them to the dryer, can you set it on low heat?

It was set on "easy" mode, but I still couldn't play it.

These sentences mean nearly the same thing:

The thermostat is always set on 68 degrees.

I always have the thermostat set on 68 degrees.

However, the second one is more personal. You'd only say "I have..." if you chose that setting yourself, like in your own home.