@LeonardS -can you document your response for @CPMINT ? Why do you believe that?
The IRS doesn't care what it is called - HELOC, 2nd mortgage, etc. if you have debt used to purchase the property and you are simply replacing (and not adding to) that debt then the interest remains tax deductible
See @CPMINT 's post and the references to Publication 936.
In the financial crisis, a lot of people cashed out equity to protect their businesses only to lose both their business and their home. I suspect the 2018 law was to prevent that going forward: the government is olay if you make a personal decision to cash out the equity in your home, but not at taxpayer expense (meaning the interest related to the cash out being tax deductible).
@CPMINT - so if you replace one debt for another, it remains tax deductible.... you get into trouble if you cashout the equity (borrower more than you are paying off).
