I think you mean “WHERE”. Depending on your living situation – apartment, townhouse, home – you may not have direct access to the water heater. In some apartments, there is a community water heater shared by all residents (or all residents on a floor), or you may have an individual heater but in a locked closet that is only accessed by the landlord. So you need to find out how this is set up in your building. There is no way for us to know.