If you are too far away he will cast nukes at you, i generally just setup just outside his shield so i dont have to move far once all 4 controllers are down. Just let the magmas kill the shitty adds from the stairs while you focus on the 4 controllers individually. As soon as the 4th controller is dead, run up close, drop 4 x mana tots, 4 x grounding, 1 wrath and 3 magmas, pop BL, pop trinkets and rape his ass dead. Pop off a couple of Chain heals around 50%, wont need much more (i dont even direct heal the tank at any point) followed by Thunderstorm. Its a 40/50 second fight once your half decently geared. If your not, then do the same but include a couple more chain heals. I still drop 4 x groundings when im close to him, but i cant recall if they get eaten up or not. As soon as i ignored tactics re: trying to straffe out of the blizzard, he died with ease. user FR aura to help combat some of the damage.

If you do the above same tactic to CofS - 2nd Boss & Mal'ganis (end boss) in CoS you will have them dead too, although the last boss will includes a lot more chain heals.

In all honesty, i think i do this same tactic for a lot of the bosses in the heroics. Unless they have some form of AoE damage that you cant out heal.

Mind you my pally tank got pretty well geared up in a couple of naxx runs, i do recall it being a little harder prior to that.

http://eu.wowarmory.com/character-sh...Nether&n=Tilce - Tank
http://eu.wowarmory.com/character-sh...r&n=Tilc%C3%AA - Shaman. Most of the others are near identical.

Keep on trying!

New changes might make it all a little easier too....who knows :x