It's a very old house but newly renovated so there has been some maintenance issues because of the cold and poor insulation.

If I sell the house, can I do the 1033 exchange too?

Cleveland and Dayton can be great markets for high cash flow and low purchase prices, but you need to be careful when navigating the neighborhoods so you're not buying in a D/F class area where no property managers will manage and where you'll never see any positive cash flow.

With a HELOC being around 9% I'd probably be paying more in interest than the money would make in the stock market.

Loan sizing varies by market, but in most areas your loan will be sized to 75-80% LTV; 1.20-1.25x DCR; 30-year amortization.

Do you own your own house? 

I need to rent my house out but thinking about going the untraditional route ie Airbnb, Padsplit etc.

The structure also allows for mitigated tenant and maintenance risk, but it has increased dependence on market movements due to being appreciation based.

You can't time the market. 

Hopefully we will be managing a handful of other STRs in the same market in the future.