Cardfight vanguard, heal triggers?

Yes, you do heal one. Since there are two types of trigger checks, heal effects vary depending on which trigger check occurs. For the instance of damage check, a card from your damage zone may be replaced (not maybe, it's may be. Huge difference) if you have the same or more damage than your enemy AFTER the check So let's say you have 2 damage, and your enemy has 3. Your damage check reveals a heal. The action would be to put down the heal trigger (making the damage ratio 3:3), then take out 1 card from the damage zone. Now as of drive check, there is also a different mechanic. The heal activates after the drive check, and BEFORE the enemy's damage check.

If you have more questions, look around Bushiroad's website for answers.

I need to point out that the "chosen answer" is partially incorrect. When taking damage, a heal trigger does NOT count itself as part of your current damage to determine whether you have enough for the effect to go off. It's still in the trigger zone and not yet in the damage zone when the check occurs.

Yes, you CAN heal on the drive check and the trigger goes into your hand. It only replaces when it is a damage check.