base + healing power (hp) * scaling

Old ele heal (cd 25s):
3560 (0.3)
1950 (0.2)
980 (0.1)
New ele heal (-33% base, +150% scaling, cd 20s)
2344 (0.75)
1310 (0.5)
660 (0.25)

old heal with 0 healing power (aka base values)
3560 + 1950 + 980 = 6490
new heal with 0 healing power
2344+1310+660 = 4314

old heal with 1k healing power
6490 + (0.3+0.2+0.1)*1000 = 7090
new heal with 1k healing power
4314 + (0.75+0.5+0.25)*1000 = 5814

Break even point (ignoring cooldown cause lazy)
(6490 - 4314) / (1.5-0.5) =  2176

TL DR : If you have less than 2176 healing power (aka everyone & their mums) then your shout heal got nerfhammered.

(aura heal also got nerfed, but i don't think other ele heals did (swapping to water, perma regen, soothing mist, weapon skills, evasive arcana)