Hello and welcome to the Tankspot Holy Priest Guide! My name is Aliena, and in this guide I'll cover everything you need to know about holy priest talents, gearing choices, gemming and basic spell usage and rotations.
This guide is up to date as of patch 4.0.3., and some info may become irrelevant or even false in the future.
Priests are the only class capable of healing that has not one, but two talent trees dedicated to healing. Currently, discipline priests can adapt to fill any role and have strong prevention spells while holy priests mostly fill the niche of raid healers. For that, we have a wide array of tools, but the healing spells you'll most commonly use are:
* Prayer of Mending
* Prayer of Healing
* Circle of Healing
* Greater Heal
* Holy Word: Serenity/Sanctuary
* Guardian Spirit
* Life Grip
* Divine Hymn
* Hymn of Hope
* Inner Fire
Those should have spots on your main action bar and be easily accessible. Less commonly used but good to keep keybound and memorized are:
* Binding Heal
* Flash Heal
* Power Word: Shield
* Desperate Prayer
* Inner Will
It is worth mentioning that Renew, Binding Heal and Flash Heal are very fast healing spells that provide a lot of throughput quickly, but they will drain your mana pool very fast and as such should only be used in emergencies. Keeping a renew on a tank when you're mostly tank healing is the exception - especially when you're in Heal Chakra, this provides a lot of extra over-time healing without you having to re-apply it.
The game mechanics have changed a lot from Wrath. Blanket-healing (a term used to describe the steady application of HoTs to counter bosses' raid-wide aura damage) is a thing of the past. No current bosses have aura mechanics, instead you're presented with big burst damage that typically gives you a longer time frame to heal your group members back up. This encourages slower, more efficient heals such as the ones mentioned in the first tier above, whereas the fast heals should be saved for emergencies.
Another thing that slows healing down considerably is the fact that health pools have increased by a lot, while the base healing of healing spells hasn't increased by that much, which results in healers having to heal more to replenish someone's whole health pool.
It is important to remember not to panic when you see someone's health pool drop drastically (unless that someone is the tank, then it's ok to panic) and instead start healing your raid back up in an efficient manner. Mana conservation while keeping your raid alive is key to successful priest healing.
(average gear in this part refers to an in-game average gearscore of roughly 350)
The new mechanic in Cataclysm that really is a niche unique to Holy Priests is Chakra. Chakra seems like a complex mechanic at first glance, but once you get the hang of it it's really easy and fun to use.
Once Chakra is activated (it works much like Inner Focus in that it affects the next compatible spell that you cast and will stay active without duration or triggering a cooldown until you use one of them), you can use it with either Heal, Prayer of Healing&Prayer of Mending or Smite. Depending on which spell you choose to activate Chakra with, you will get a buff to certain spells while your Chakra state is active. The original Chakra cooldown and duration is 30 seconds, but it can be prolonged by talents, so if you make use of that, you don't have to recast it every 30 seconds.
On top of the passive buff, if you take the talent "Revelations" your Holy Word: Chastise will change into a different spell depending on which Chakra state you enable.
When entering Serenity "Heal" Chakra state, your direct healing spells such as Heal, Flash Heal and Greater Heal will have 10% additional crit chance and casting them will refresh the Renew duration provided Renew has been cast on the target. The "Heal" Chakra state will enable Holy Word: Serenity, which is an instant but relatively small heal that also increases your critical strike chance on that target by 25% for 6 seconds. This Chakra state will be your bread and butter spell in 5-man instances, heroics and quite a few 10-man raids.
When entering Sanctuary "Prayer of Healing" Chakra state, all of your AoE healing spells will heal for 10% more and your Circle of Healing cooldown is reduced by 2 seconds (from 10 seconds down to 8). The "Prayer of Healing" Chakra state will enable Holy Word: Sanctuary, which is a targetable AoE heal that heals each person within it for roughly ~600-900 health every 2 seconds for 18 seconds (9 ticks). The healing effect is reduced if more than 6 targets benefit from Sanctuary.
Prayer of Mending is an amazing spell that no other class currently has an equivalent to. Once used on a target, it'll take effect once that target takes damage and after healing it, will bounce to another raid member in range. Prayer of Mending has 5 charges and will bounce until either its charges run out or the current target does not take damage within thirty seconds. it's on a 10-second cooldown and should be used on cooldown on a tank or someone else that will predictably take frequent damage. With average gear (ilvl350), it heals for about 6000 on a non-crit and 8000+ on a crit.
Prayer of Healing is a party-wide AoE healing spell with a 2.5-second cast time and a 40 yard range. This will be one of your most-used AoE healing tools and also one of your most mana-efficient AoE heals. With average gear it heals for about 8000 on non-crit and 11500+ on a crit. This should be used whenever whole parties are taking big chunks of damage, especially if said damage is predictable and you can start casting PoH before the actual damage happens. As a fun little comparison, it costs less mana to cast than Flash Heal.
Circle of Healing is a very potent smart AoE healing spell that affects 5 or up to 6 targets if glyphed, with average gear heals each target for about 4000 non-crit and 5500-6500 on crit and has a 10 second cooldown timer. Circle of Healing should be used whenever 3 or more targets in the same general area take damage. Since it's a smart heal, you're not able to pick who it's going to heal, but it'll pick the 5 (or 6) lowest health raid members within 18 yards of the target. CoH is an instant spell so it's excellent to use while moving around.
Lightwell, frowned upon by priests and laughed at by everyone else for many expansions, has completely changed its tune. Lightwell is your highest healing-per-mana spell and will save many, MANY lives - if only you can get people to click it. However, this is a constant work-in-progress by priests and raid leaders the world over, and many people have become accustomed to clicking the damn lightwell at this point. Keep the good work up! This is a group effort. With average gear, Lightwell will heal for about 6400 and tick three times for a total of roughly ~19200 health. Lightwell can be placed before a fight even starts, which means you're able to recover the mana spent on it before a pull, essentially making it free healing. Lightwell lasts for 10 charges (15 glyphed) or 3 minutes.
Heal is your new bread-and-butter single target healing spell. Most trivial AoE and tank damage can be healed up over time by just using Heal. It is incredibly mana efficient, and you will basically find yourself gaining mana while using it provided you have a few raid buffs. Don't forget to activate the corresponding Chakra state when you know you're going to be using a lot of direct healing spells. Heal has a 3 second cast time (2.5 with talents) and with average gear heals for about 8000 on a non-crit and 12000 on a crit.
Greater Heal will be a huge help to you when you find yourself as tank healer, or even just when you're helping out with tank healing or a random raid member takes a large single target damage spike, such as Magmatron's Acquiring Target ability. Greater Heal has a 3 second cast time (2.5 with talents) and with average gear heals for about 22000 on a non-crit and 32000 on a crit.
Holy Word: Serenity and Sanctuary become active when you activate the corresponding Chakra state. Serenity is most useful while tank healing as it provides a rather small instant heal but also increases your critical strike chance on that target by 25% for 6 seconds. Line up a few Greater Heals after Serenity to hopefully heal your tank back up quickly.
Sanctuary is most useful when your entire raid is stacked up in one spot and taking AoE damage. It is not recommended to use Sanctuary when less than 6 people are grouped up and even then it is a toss-up, as it has a very hefty mana cost of roughly 10000. It does however last for 18 seconds and will heal everyone within it for roughly 600 health every 2 seconds (900 on a crit). The healing effect is reduced if more than 6 people are within the Sanctuary.
Guardian Spirit is useful in any situation where you expect someone to have a relatively good chance of dying. Preferably, this is placed on tanks that take a huge dip, but can also save other people that have neglected to get an essential buff (like Grounded/Levitate on Ascendant Council) or yourself when you've done something dumb. It also increases healing received on the target by 40% for its duration, and as such is a great help in restoring a tank's HP pool. Sadly, its glyph got changed, so now its cooldown is 3 minutes at base value, 2.5 minutes glyphed.
Life Grip is our new toy, and much like Guardian Spirit it can help save people from dying. This is most useful when you catch someone standing in bad stuff on the ground or wish to assist them in kiting. If you have the Talent Body & Soul, using Life Grip on someone will also increase their movement speed for 4 seconds afterward.
Divine Hymn is an extremely potent and smart channeled AoE heal on an 8 minute cooldown timer. This is comparable to a druid's Tranquility spell, except every tick it'll pick the three nearby lowest-health targets to heal regardless of party. It'll tick a total of 4 times on up to three people each time and heals for roughly 9000 non-crit and 13000 on a crit.
Hymn of Hope is also channeled; restores mana to 3 nearby raid members, ticks up to 12 times (total, so up to 4 ticks per person) and increases their maximum mana pool by 15% for 8 seconds. It typically picks the three people with the lowest mana, which means you won't neccesarily be one of its targets. However, if you use it while your mana pool is extremely low, you're likely to receive some mana back from it. In any case, it's a great mana restoration tool for your raid members and they'll most likely be thankful no matter when you use it.
Inner Fire will be your most-used buff of choice. It greatly increases your armor value but most importantly increases your spell power by 532. This effect lasts for 30 minutes or until cancelled.
Renew should be used on tanks whenever you find yourself tank healing in Heal chakra. However, it has lost most of its appeal in raid healing as renew spam is just not sustainable anymore. You will find yourself running out of mana constantly if you try. Try to keep usage of Renew to tank healing and as a filler spell while moving. With average gear, Renew heals for about 2800 on a non-crit and 4200 on a crit.
Binding Heal can be used whenever you take damage at the same time as another person AND this damage needs to be healed quickly. Binding Heal has a 1.5 second cast and the same mana cost as Flash Heal and heals for slightly less on the individual targets, but since it does heal two people at the same time, it's more efficient to use than Flash Heal. Neither of them should be used outside of an emergency situation, though. With average gear, Binding Heal heals for roughly 13000 on a non-crit and 16000 on a crit.
Flash Heal has become very expensive to cast in patch 4.0.1. As trade-off, it now heals for signficantly more, about 16000 on a non-crit and 23000 on a crit. It also has a 1.5 second cast time and should be reserved for extreme emergencies as it will quickly drain your mana pool.
Power Word: Shield is an amazing tool made awesome by talents for disc priests that loses a lot of value for holy priests, but useful for two reasons: Firstly, if you have taken the talent Body and Soul, it becomes situationally useful (for instance, to give a person running a debuff out of the raid a speed buff) and secondly, it is an instant spell so you can cast it while running. Mind you that disc priests will not be very happy with you if you decide to randomly shield people, since it places a weakened soul debuff on the target that prevents re-application of Power Word: Shield for 15 seconds.
Desperate Prayer is a rather weak instant self-heal with a 2-minute cooldown that can be used as an emergency heal when you see your own health dipping low quickly, or when you know you're about to take an inevitable chunk of damage. It heals for about 10000 on a non-crit with average gear and 13000 on a crit.
Inner Will is the other self-buff you can choose to use instead of Inner Fire. Inner Will will give you a passive 10% movement speed increase and will reduce the cost of your instant cast spells by 15%. However, the movement speed increase does not stack with boots- or head enchants and the only instant cast spells you'll use on a regular basis for regular raiding are Circle of Healing and Prayer of Mending, so Inner Fire will be the better choice in most cases.
That covers just about any healing spell you'll ever need to know about for raiding purposes.
Fairly common specs:
6/32/3 (25-man throughput)
6/33/2 (10-man mana efficiency)
3/33/5 (Darkness instead of Twin Disciplines)
Next, let's talk specs. With the talent spec consolidation that was implemented in 4.0.1, there is not much wiggle room. You HAVE to spec 31 points into holy before you can touch other trees. There are a total of 36 points in the holy tree, so you can skip up to 5 of them. I'll go over the staple talents that you really should have in your spec.
In the first tier we have Improved Renew, Empowered Healing and Divine Fury. Empowered Healing and Divine Fury are no-brainers that every priest should have in their spec. Improved Renew is still a good talent and one you should pick up, even if you're not using Renew much right now.
In the second tier we have Desperate Prayer, Surge of Light and Inspiration. Desperate Prayer is situational, but if you think you can get used to it and will use it in situations where your life is in danger, it's worth spending the talent point. If you won't use it, skip it. Surge of Light now gives you a 6% chance to trigger an instant, free Flash Heal when you use Smite or Heal. However, in 25-man content, you'll rarely find yourself using Heal, and statistically speaking, a Surge will only trigger on every 17th cast, so you should mostly spec into it if you do 5- and 10-man content. Inspiration is a no-brainer, do take it.
The third tier greets you with Divine Touch, Holy Concentration and Lightwell and Tome of Light. Lightwell and Holy Concentration are staple talents, definitely take those. Tome of Light is useful especially if you find yourself utilizing a lot of Heal Chakra, and Divine Touch is a good option in lieu of much choice.
In tier 4 you will find Rapid Renewal, Spirit of Redemption and Serendipity. Spirit of Redemption no longer carries its 5% spirit component, but can still occasionally be useful in 5-man and raiding content. If you prefer Surge of Light or Desperate Prayer instead of SoR, take either of those instead. Serendipity now is activated by Flash- and Binding Heal and as such you won't get quite as much use out of it as you used to, but it is still nice to have in emergency situations to heal both a tank and/or a party back up quickly.
Tier 5 awaits with Body and Soul, Chakra, Revelations and Blessed Resilience. Blessed Resilience is now basically a pure PVP talent, don't bother taking it. Chakra and Revelations are staple talents, pick up both. Body and Soul is increasingly useful in many raid and instance situations and now also gives a speed boost after using Leap of Faith (Life Grip).
Tier 6 has Test of Faith, State of Mind and Circle of Healing. Circle of Healing and Test of Faith are staple talents, take them. State of Mind is very convenient and one of the better talents to spec into.
Lastly, we have our final 31-point talent, Guardian Spirit. Although its usage is occasional, it's an incredibly powerful tool that should not be missing in any holy priest's toolbox. Sometimes you'll be assigned to use it in a cooldown chain, other times you'll be able to use it at your discretion when a tank or another raid member is close to death. Either way, it ends up being useful in many situations. Learn to love and use it!
Now, for the other trees - this is actually where the biggest spec variety awaits you. When you look at the first tier of both the discipline and the shadow trees, you'll find 4 worthwhile talents to take. Keep in mind that you have at most 10 points to spend, though.
The Discipline tree has Twin Disciplines and Mental Agility, whereas the Shadow tree sports Darkness and Veiled Shadows. Twin Disciplines is a direct 6% healing increase and hence should be a no-brainer. If you use a lot of instant cast spells but suffer from mana issues, Mental Agility might be worthwhile for you. On the other hand, Darkness in the Shadow tree gives you a 3% increase in spell haste and Veiled Shadows decreases the cooldown of your Shadowfiend by 1 minute. Twin Disciplines and Darkness are direct HPS increases, so if you don't have mana issues you're best off spending your points here. However, if you do have mana issues, you may instead opt for Twin Disciplines and Mental Agility. If you really cannot sustain your mana throughout a fight, Mental Agility and Veiled Shadows might be something to try out.
This also goes for glyphs. With 4.0.1, the glyph system got a huge makeover. We now have three tiers of glyphs - Prime, Major and Minor. Prime Glyphs, according to Blizzard, are meant to be direct performance increases, while Major Glyphs are more situational and Minor Glyphs are for fun and convenience.
There are a total of four useful Prime Holy Priest Glyphs that you should pick up.
* Glyph of Prayer of Healing
* Glyph of Guardian Spirit
* Glyph of Lightwell
* Glyph of Renew
While Glyph of Flash Heal and Glyph of Renew are also Prime Glyphs, neither of them bring a performance boost in the currently widely accepted raid style. However, if you've managed the miracle of making Renew sustainable and find it gets a lot of use (or the people you play with still don't understand the concept of Lightwell), you may wish to exchange the Lighwell or GS glyphs for Renew. For most priests, this is not recommended.
As far as Major Glyphs goes, you have a little more wiggle room.
* Glyph of Circle of Healing
* Glyph of Dispel Magic
* Glyph of Mass Dispel
* Glyph of Psychic Scream
* Glyph of Fade
* Glyph of Holy Nova
* Glyph of Spirit of Redemption
These are all Major Glyphs you may want to look at and evaluate. Glyph of Circle of Healing should be a staple in any holy priest's setup. Glyph of Dispel Magic provides a small healing boost, while Glyph of Mass Dispel brings your Mass Dispel cast time to 0.5 seconds. To me, these seem to be the most valuable in any given situation, but if you do not make use of either type of Dispel much, you may instead choose to opt for Glyph of Holy Nova or Spirit of Redemption. One lets you pretend you didn't just die for 6 seconds longer, the other caps your Holy Nova at a 1 second global cooldown without any additional haste. Fade/Psychic Scream are situational, but may prove useful in some boss encounters.
Minor Glyphs will not directly affect your throughput or efficiency, but Glyph of Levitate and Glyph of Fortitude are usually good picks for convenience. Also, Glyph of Shadowfiend is moderately useful if you tend to summon the bugger in the wrong moment and it dies instantly to some sort of annoying AoE.
==Gearing, what to aim for==
As one of three cloth caster classes, you'll always face gear competition. It's all the more important to know what you want and look for in gear. Lots of stats are good for us, I'll list them in the order of how I rate their importance.
Intellect, since 4.0.1, now grants you spellpower and hence replaces spellpower as the easiest and most straightforward throughput stat. The more Intellect, the bigger your heals. On top of that, intellect increases your mana pool and hence affects how much mana you regenerate from replenishment, shadowfiend and hymn of hope; it gives you critical strike rating (around 150 Intellect equal 1% critical strike rate) and slightly increases your mana regen (this function is tied in with spirit). In short, it's an incredibly beneficial stat.
Mastery is a new mechanic implemented in Cataclysm. Mastery does something different for every class and spec. For holy priests, Mastery causes Echo of Light, which means that any direct healing spell you cast puts a HoT on the target for 6 seconds. This HoT heals for a percentage of the original heal and the percentage is based on your mastery rating. The base rate with 0 mastery is an 8% HoT, and with each additional full point of Mastery (179.3 Mastery Rating), the percentage increases by 1.25%. Echo of Light currently accounts for about 9% of my total healing over a fight and is a direct throughput increase.
Haste is still a good throughput stat, but has lost a lot of its value since we now have to watch our mana more and use less instant cast spells. Haste gives you faster heals, but on the flip side it also makes you spend mana faster. Currently, around 12.5% haste is sufficient for most priests (128 Haste Rating equals 1% Haste). Past that number, you will probably find it more useful to stack mastery. For more math-y information on Haste, I recommend the Elitist Jerks thread that is constantly updated with Theorycraft. http://elitistjerks.com/f77/t110245-...st_compendium/
Spirit is now a direct mana regen increase and not much else. You should make sure that most if not all of your gear has spirit as a stat to ensure you don't run out of mana during a fight, but do not gem or enchant for it unless there is no better option.
Critical Strike Rating does what it says it does - it gives you increased chance to crit on your spells, whether they're damage or healing spells. However, as throughput increase it is fairly unreliable, so it's low on your priority list. If you pick up a piece that has crit rating and haste rating on it (but no spirit), you should consider reforging some of the crit chance into either haste or mastery rating.
As for Stamina... we all need it. Stamina automatically goes up as your gear level increases. Unless your gear level is way below the level of content you're doing, you'll pretty much always have enough of it.
==Enchants and Gemming==
Holy priest enchants are very straightforward. I'll list what's generally considered the best choice for each slot.
Head: Arcanum of Hyjal, the 60 Intellect/35 Critical Strike Rating enchant, available at the Hyjal Quartermaster at Revered Reputation would be the best choice.
Shoulder: Greater Inscription of the Charged Lodestone, which adds 50 Intellect and 25 Haste Rating to a shoulder slot and is available at the Therazane Quartermaster at Exalted Reputation. Your second best bet is the Lesser Inscription of Charged Lodestone, available at the same place at Honored Reputation. Obviously this does not apply if you're a Scribe.
Back: Darkglow Embroidery for a tailor if you need additional regen, Lightweave if you want throughput, 50 INT otherwise.
Chest: 20 to all Stats or 40 Spirit would be your best bets.
Wrists: You have the choice of 50 Spirit or 50 Haste here, depending on whether you want additional Regen or Throughput.
Weapon: Heartsong and Power Torrent are both good choice. Power Torrent will occasionally proc an INT buff while casting, Heartsong will occasionally proc a spirit buff. Quote (and credit) from EJ on Weapon enchants:
Hands: 50 Mastery and 50 Haste are both acceptable enchants.For Holy, Heartsong will net about 40-50 more mp5 than Power Torrent. Timing shadowfiend with a PT proc will increase the regen benefits of that enchant. For Disc it’s much closer, with Heartsong having about 10 mp5 advantage over PT. So with good shadowfiend management PT could be nearly equal for regen.
Legs: Powerful Ghostly Spellthread will give you 95 Intellect and 55 spirit.
Feet: Lavawalker which adds 35 Mastery and a slight run speed increase or alternatively 50 Haste or 50 Mastery.
As far as gemming goes, there are different ways to gem your character. You can stack just one stat that you're lacking or that you favor and neglect all others or you can choose to gem for socket bonuses.
I personally prefer to gem for socket bonuses using Brilliant Inferno Rubies (40 INT), Reckless (20 Haste, 20 INT) or Artful (20 Mastery, 20 INT) Ember Topaz and Purified Demonseyes (20 INT, 20 Spirit). That way, I stack up on Haste/Mastery, Intellect and Spirit, the stats that are most important for my playing style. Alternatively, you might prefer to gem all Brilliant Inferno Rubies. This will likely be mathed out in the near future, so stay tuned.
There are two meta gems that you may find interesting. Widely considered as the best choice for healers is the Ember Shadowspirit Diamond, which gives you 54 Intellect and 2% maximum mana.
Another slightly less valid choice would be the Revitalizing Shadowspirit Diamond, which gives you 54 Spirit and 3% increased critical healing effect. Early testing points to the Ember Diamond resulting in more throughput.
That about covers the basics of successful priesting. Thanks for reading!
Last edited by Spiritus; 11-28-2010 at 02:12 PM.
Uploading to the server I hope?
Excellent guide. My alt priest is disc, so its nice to see how the other side lives.
Since this covers some very basic elements maybe you could add in a section about correctly using mana-regen tools. Mainly things like hitting hymn of hope while manatide is down and correct times for using shadowfiend(i.e. instead of throwing it out 2 seconds before dreadscale is downed, wait until icehowl comes out, so it isn't wasted by having nothing to attack).
p.s. I want a dragon kite.
Gonna respec my priest from Disc to Holy now...Amazing Guide!
Curious, would you not recommend getting Springy Arachnoweave - Spell - World of Warcraft if you are an engineer?
Last edited by Abolita; 10-12-2009 at 05:58 AM.
I was waiting for this, time to respec my Disc PVP dual to Holy and gear up
Bronzebeard - US
Aliena, thanks for the great guide.
Do you use an add-on, specifically or not, to watch your serependity stacks? or something that warns you that you have 3 stacks ready?
Can you pls post the Disc spec that you use i am wondering what im doing wrong.....as some vids ive seen your Disc Spec as Top healing done......if you have time that is i know im not only one,....i hope lol. doesnt have to be this elaborate just an edit maybe?
A very nice Basic Guide, I will have to post a link for all the wanna-bee alts leveling in my Guild.
I had another question for Aliena:
You said Intellect is the most important stat as it contributes to many things (Stats, talents, procs..)
Do you think a Holy Priest in ToC25 / H. ToC10 gear should wear any intellect trinket in a common set?
Hey Aliena, watching you heal in your videos, and listening to you explain some of the points in holy actually sound like fun, healing i could enjoy, my main is a paladin and i hate healing on him basically, not many fun healing abilities i guess.
Anyway, i lvled my priest to about 15, does it pick up in pace once you get a few more lvls? Also do you have any suggestions about which spec to lvl as, i know many say shadow, but right now its so slow, it feels like i am watching paint dry.
Leveling a Holy priest - WoWWiki - Your guide to the World of Warcraft
[Priest] Solo Leveling Guide
[Priest] Solo Leveling Guide
[Priest] Solo Leveling Guide
Personally I'd level to 40 and then switch to shadow. Because it's laz0rs, pew pew.
And priests are a pain to level in the beginning, but after level 30 it starts to pick up it's speed and at level 40 with shadow form you'll feel pretty mighty. And it's fun. So don't give up quite yet.
"We have two ears and one mouth for a reason." - Buddhist belief.
I do prefer running with an intellect trinket. It came down to spark of hope vs. meteorite crystal to me, and I absolutely prefer the int. I would've liked the trinket from mimiron25, but alas, I never got lucky with that one. If you're very attached to your spark of hope and play well with it though, by all means keep it.
As far as leveling goes, shadow isn't very viable til you get shadowform. The first 40 levels are a drag but badge gear helps out tremendously.
You ask what you are doing wrong because you are a disc priest and you see some other disc priests top the healing meters.
Your main problem is you chose the wrong guild. If a disc priest is at the top of the meter, in most cases it is because the dps is avoiding avoidable damage and 90% of the healing needed is tank healing. For example, during the Hodir encounter, a raid healer should be bored through most of the fight, since the only unavoidable damage is Frozen Blows and the occasional top off after a Frost Nova. A disc priest assigned to heal the tank should top the meter every time. If the holy priests in your raid have more total healing done on Hodir, it is because your dps'ers are getting hit by Icicles, getting 4-5 stacks of Biting Cold before they decide to start moving, or don't get on top of the snowpiles before Flash Freeze.
I would like to add a shout-out for Lightweave Embroidery over Darkweave for Tailors, Ember Skyflare Meta over Beaming Earthsiege, and even taking 1 point out of Meditation to put into a throughput or utility talent.
With Shadowfiend, Hymn of Hope, Mana Potions and Arcane Torrent (for Blood Elves) I find that I almost never get close to running out of mana (and I usually don't even use the pots or Hymn). We generally run 6 healers and don't do Heroic or Hard Modes, so it might be different if you run fewer healers. But I'd definitely counsel examining how often you go oom, and if it's almost never, consider some changes to lower regen and bump up throughput.