I use my basement Harmon P38 to supplement my geothermal heating during cold snaps (low teens and below). It's a great combination. My question is if I were to buy a ton of pellets would I have an issue using 2-year old pellets? I would probably use a half-ton during a heating season and the rest the following heating season (maybe some in a 3rd year - depending on how bad the winter is). They would be stored in my basement with humidity maxing at 55% in the summer. Thx...