A general question... Hopefully nearly coming to the end of a very cold week here in Ky and near the end of the heating season. I sometimes turn off the aux heat (electric) to see how the geo is performing on it's own. At the beginning of the season it would put out 92.f. Near the end of the season (and after days of below zero f temps) it's struggling to put out 82.f! I understand that the loop temps will drop over the season, but does this (should this) always produce lower heat output at this time of year?