Originally Posted by
Xenic
This is incorrect ( and I'm shocked you didn't know this!)
Green heals stack up to a total of 2. Doesn't matter what classes cast them. This also takes into consideration Demo Pet heal, Conq Banner heal (if they even still have that... I don't know) and DT heal. So if you have a Demo, Tos, Pom, only 2 of those 3 heals would actually stack... the third doesn't.
Blues. Only ONE blue heal can be on you at any given time. The reason people say to wait for the blue heal timer to end before casting a new one on you is that the first tick of the blue heal was a small burst. I don't know if this mechanic was changed or not (It's been a really long time since I studied my healers) but even if it is still the case, it's more beneficial to keep the blue heal on them and lose the bonus from the burst than it is for them to NOT have any heal ticking.
Big heals. These give a debuff on the target which is double the cool down. So if your big heal has a 30 sec cool down, the debuff will be 60 seconds. This debuff is class specific, so you can have a BS, POM, and TOS debuff on you.
Remember, ALL HOTS are to prevent, not to rescue. Burst heals are your rescue measures.