Insane amounts of water used.

Hi!
I've aqquired som guys to fix my problem, and it seems to be a problem with the engine head and/or the head gasket. The car uses a LOT of water in a short period of time, but I van't spot any leaks. I think there is water in the oil, the car produces a lot of white exhaust, and last week, the engine started to produce a lot of white smoke/steam. I think this indicates that either the head gasket or the head is broken. The guys I've hired to fix the problem says it's the head, so I'm goin to change both the head and the head gasket for good measure. Wil this fix my problem? :)