Deductions & credits

Lets say you get a heloc and you make a 25k draw to lock in the 'introductory' rate.  For example, you draw it as cash into a checking account then pay for home improvements using that checking account, does that sill count?  If so what kind of documentation would I want to save here?  I'd hate to lock in a introductory rate, only to find its not tax deductible.