Hi all -

I'm in a 1930's single family, and looking to install an overhead bath fan/heater/light, many of which call for a dedicated 20amp circuit. First, how do I know if I have 14 or 12 gauge wiring? I assume I have 15 amp only, but can my wiring withstand a 20 amp breaker, or do I have to rewire from the 2nd floor to the basement all just for this unit?

Thanks for the advice.