It sounds like you will breakeven which is better than carrying a negative cash flowing property for years.

Carry appropriate types of insurance.

A Heloc is a open end mortgage like a credit card so its an additional trade line on credit, cannto never be used as an Asset, PITI reserve, and its a DTI killer in most cases.A heloc is also usually set up on a shorter term versus a mortgage, carries a Higher interest rate, and most carry a interest only with a prepayment penalty.

Hi,I've been researching seller carry back financing for multifamily, and have talked to a few commercial lenders willing for the seller to carry the down payment for a apartments.

@Carrie K.

Be prepared for things like carrying costs, permits, and any surprise repairs that come up.

That is what it looks like and it is also what Carrie told me when I spoke with her about it.  

In fact, he carried it a couple of steps farther.  

As I matured in my career I have expanded my lender network and product line with the goal of carrying a very wide variety mortgage products at the best rates.

But, when it comes time to put the deal together and pull the trigger: work with a seasoned real estate attorney with experience in structuring seller carry deals and writing thorough docs that cover your interests, especially with the "what ifs?"