The S8X2 carries an 80% AFUE rating — a clear sign that this furnace uses most of its fuel for heating.

With an AFUE rating of 80%, the S8X1 can help reduce monthly energy bills while supplying you with the heat you need at the coldest times of the year.

The S8B1 is rated up to 80% AFUE, meaning it’s designed to use less energy to warm your home. For you, that means more comfort and lower energy use.