Psion: Egoist (if Kalashtar) or Shaper (if Warforged)
Transfer your allies wounds to yourself, heal self. Works best with starting level of 5+... before that you only have the Heal skill.
Body Adjustment (general psi 3rd lvl): You heal 1d12 damage... (use the Extra power feat to take this as a 2nd lvl Psy-Warrior power, cheaper cost).
Body Purification (general psi 3rd lvl): you restore 2 points of ability damage...
Empathic Transfer (Egoist 3rd lvl): transfer another's wounds to yourself. You heal 2d10 (base) and take half of the result or take the burden of rolling secondary poison/disease saves.
Share Pain (general 2nd lvl) +
Psi-Crystal Affinity feat: Especially useful with Vigor manifested.
Vigor (general 1st lvl): +5 temp HP to you per psi-point. This makes a nice buffer for when you manifest Empathic Transfer.
I had a Warforged "healer" who did this with psionic Repair Damage (3d8 +1 per ML, augment +1d8 per 2 Psi) rather than Body Adjustment.
edit: Alternately, one or two of the Complete Psi base classes can (I think) heal... something about "mantles". I don't own that book though...
Edit again: the Life Mantle has a lvl 1 Psi power... 2pts of healing (or dmg vs undead) per psi-point. Rather weak, but better than what arcane can do with a lvl 1