1031 to Primary Soon to be Rental

Hi everyone. I have a rental house that I've owned for just over a year. I have to sell it for personal reasons. I also have a primary residence that I'm going to turn into a rental and buy a new primary residence. Can I use the 1031 to recast the mortgage on my current primary but soon to be rental? Any other strategies for using 1031 money in this situation or is it only for purchase of a new rental property?

Thanks in advance