Monterey gravity, top-vented wall furnaces require no electricity for operation, a matchless pilot igniter and automatic temperature and safety controls. Each furnace includes a thermostat that may be mounted on a wall or on the cabinet of the furnace. The furnace is vented through the roof to the outside (venting material not included) allowing for installation on an interior or exterior wall. May be recessed into the wall between 16" studs or surface mounted.