Then 1031 exchange to a bigger property (more units).  

You can combine the illegal unit with another to make it legal and bigger.

Bigger Pockets podcast #114

So I have been listening to bigger pockets for I wanna say about 4-6 months now, and currently reading rich dad poor dad.

You did not specify electric or gas or the size of the unit by I use them often because:-For smaller units they are cheaper and easy to install-Take up very little space-Are efficientThe negatives:-May require a breaker reconfigure as the usually require 2 30amp breakers-In bigger properties with a long run say to the other side of the house, it takes a minute or 2 to heat up

If you 1031 from a property that had lot of equity you could jump into something bigger.... then see even more appreciation. 

It's a little bigger (4 beds, 2.5 baths) than the average rental (2-3 beds) in my area, but I'm surprised that I haven't really gotten any hits.

@Jeff PaganoWelcome to Bigger Pockets.

The good deals sell fast ,so if you see something your interested in analyze it using the calculators on bigger pockets and make a choice.

I joined bigger pockets about 4 years ago then took a hiatus.