ovearheating + voltage error

[Calin]

crosshair formula V
fx-8350 turbo core off running at 4ghz
corsair vengeance 1600mhz (xmp profile)
thermaltake smart se 530w
antec kuhler h2o 650
asus gtx 970 turbo OC

for the past 2 months my cpu started to report higher and higher temperatures. it got to the level where i can't play any game without overheating and reaching the shutdown point. for the past 3-4 weeks my core temps reach 50-52 C while watching videos in chrome on youtube. if i do nothing, temps are 38-39 C. today i got another error... voltage... something is really wrong and i cannot determine what it is.
i haven't fiddleled with any of the setting prior to the overheating problems so... i am inclined to think it's hardware related, but what ?!

HELP WANTED !

[Legolas]

Is your antec kuhler h2o 650 working? Check thermal paste is applly well on the coldplate. Also, check if your fan connector of H20 is connected to the Chasis_Fan 3 pin connector in MB.
Is your h20 650 fans running full speed