Low Ejection Fraction

Hello,
Does having EF between 20-30% means one has heart failure ?  My BNP level is not elevated. My EF has been low for many years (under 30%). I have had stress test done annually for many years. Until this year after the test my regular cardiologist used to tell me that things are as they were last year and no need to change treatment (ACE, beta-blocker and Lipitor). A few months ago after rushing to ER after chest pains, another cardiologist told me that no MI but EF is low, get an ICD which I did. I also had overactive thyroid gland which was treated with radioactive iodine. Now i take syntheroid (synthetic thyroxine) to compensate for the Ioss of the natural hormone.I am also an insulin taking diabetic.
I  work full time , don't have shortness of breath or fluid retention. Do I have heart failure ? Am going to get the classical HF symptoms sooner or later.?
Thanks.