Heartache may or may not be subconscious. If you know the cause is the memory of an ex-lover, than it is a rational and conscious association, but if you feel heartache after hearing a song you never heard before without the slightest clue of why, it is a subconscious association. Your heart may ache and you may cry because of the new song, but there being no association beyond that, means the reaction is out of your control.
Another example is when you get angry at someone for raising their voice at you, such as a wailing infant. At first the aggrevation seems like a conscious decision, but later when you realize the anger doesn't stem from the child crying but from unresolved issues about your own upbringing pushes the aggrevation into the realm of unconscious reactionary behaviour (also called instinct, which stems from the reptilian brain), not an aggrevated reaction to a pissed off baby. If we really love our children than anger has no place in our hearts because unconditional love overrides any hasty decision to become over emotional at an infant. Even distress is overridden because the parent, after the initial shock, knows how to calm their newborn down. Any lingering emotion, even the good ones, are usually associated with unconscious reactions of our neurochemical makeup. Our ear drums may be shocked by the torrent of noise but that has nothing to do with our emotions only our physiological reactions.
Fear or happiness in a dream state all relate to the subconscious unless of course we are lucid. But even in lucidity our dream selves still feel random emotions. You can be aware that bad dreams make you wake up in a sweaty mess and remember the dream itself but without knowing that the somatic expression of sweat stems from how the dream is a symbol for the loss of your lover you are unconscious of the cause. The line between conscious and subconscious in relation to emotion stems from the cause of the association not the association itself.