My current build is 32/7/2, which is a pure healing build and has very weak damage. However, if getting your healing numbers higher is your goal, then I'd consider going with this spec as well.
I'll give you a few tips that I give other people who ask me about how I get such high healing in WZs.
Tip #1 - Raid frames are amazing to have, but not always the best! What I like to do, and what has worked for me very well, is to TAB target an enemy and then ASSIST the enemy. This gives you the target of a friendly player (more than likely) and someone who is probably about to get focused on. Once you get this technique down, you can pull it off in literally a fraction of a second. Give this a shot and let me know how that helps.
Tip #2 - There is never a bad time to put a shield on someone! It's a guaranteed bit of healing if they take damage, and if they don't take damage then no big deal. If you play the game right, you can throw out shields without worrying about taking too much of a hit on your energy. If you see the enemy coming at you and your allies, put a shield on them right away. Since your ally gets a debuff for having a shield cast on them, it's best to use it early so that your chances of the debuff wearing off before their shield gets sacked is much higher. That way you can put another shield on them ASAP.
Tip #3 - Any chance you can to throw on a Rejuvenate (HoT) before you cast another healing spell is essential. With your talents, your HoT spell gives all of your other heals some sort of benefit as well as giving your allies a small armor bonus. If you don't take advantage of your HoT you'll probably find yourself going OOM.
Tip #4 - Survival is the name of the game! Make use of your crowd control to escape and don't overlook SPEED. If things look like they are going south, pop your speed ability and run around a corner to get in a quick heal or two. Also, you have a spell to SLOW targets. Use this all the time. It's unbelievably handy if you have one person beating on you. It's especially handy against melee users, such as Marauders and Juggernauts. The delay on use of your AoE knockback ability makes the spell very unreliable in a clutch situation, so use it early.
Tip #5 - Be situationally aware of where your allies are while fighting! Your AoE heal can be a source of amazing healing if used in the right spots. For instance, Void Star is amazing for this spell. If you have a bunch of allies fighting at the door, throw them an AoE heal. Chances are they will stay in the ring longer than people who are running around trying to kill random people. Also, don't be afraid to use it for yourself for survivability if you have to. That AoE heal, combined with your HoT heal, is a very nice source of healing ticks. When you throw in your channeled heal and shields you are able to keep yourself up through almost anything (Powertechs being the exception)
Tip #6 - People are out to stop you from healing! A lot of people use the technique of stop casting to fool people into wasting an interrupt and getting no benefit out of it. However, in SWTOR, I've found that it works pretty well to simply cast your fasted heal (and worst heal) and let them interrupt that. Most of the time people are just looking for a cast bar to interrupt and not the actual spell being cast. What I do from time to time is use my fast heal, and while it is casting I'll be spamming on another heal. The second it gets interrupted you'll start casting your new spell. This won't work against really good players, but on medium level players and even some experienced players it works like a charm.
Out of all these tips, I'd say practicing on Tip #1 will increase your heals the most, next to simply staying alive. Targeting in SWTOR is somewhat terrible, so assisting the enemy is a very good workaround. I used this method in other MMOs that I played as well.
I hope this helps you out a little bit, as well as any other healers who might be looking for help in Warzones.