i replaced the head gasket because of this problem

and bout a new head and didnt fink id have the same problem again did it before but the fan was on constant and still did it when i got the car fan was hooked up to runn from ignition i had it rewired to the fan switch to work which it did but hasnt kicked in when running it the last 2 times just over half way
if the fan doesnt kick in would the water boil ??
only last 10mins before it does