Technically speaking, the ASUS Crosshair IV Formula has the same NB chipset as the GIGABYTE GA-890FXA-UD5. I'd keep the Crosshair because it's a very nice board. Your board may have a problem, but it may not. If the NB is too hot you could probably feel the heat coming from the NB heatsink. The problem may be that the heatsink is too small or something else like it's not properly mounted. I've personally never heard this before but that would be the most likely problems, otherwise voltage.
Fixing it depends on the problem.