Paying off a mortgage with a home equity line of credit (HELOC) is technically possible. It is essentially a way of refinancing your loan, but actual refinancing is a much simpler option for reducing an interest rate on a mortgage to pay it off more quickly. The interest-only repayment option is an attractive feature of a HELOC. However, at the end of the draw period, the interest and principal will be rolled into one amortized monthly payment for a loan term of 15 years. If you are not prepared for this, then the increase in your monthly payment could catch you by surprise.