(and the views are amazing combined with $CAD being low within international market)What you need to ask yourself is what your goals are?

However, the bank rejected my application because my DTI would become too high with the combination of the HELOC and mortgage payment. 

Factors tied to the escalation in values would includeDecrease in listing availability Increase in buyer demand (at least in proportion to listing availability)Interest rates being blissfully lowBuilders being businesses that needed to hedge their bets early in the COVID mania and reduced new construction paceCurrently commodities needed for construction are significantly elevated over pre-COVID levelsThe GOV is passing out cash like candyAll of these forces and a few others combine to create an up-and-to-the-right kind of housing market. 

Never a bad combination if you have aspirations to scale more or do more business in any way.On a related note:  If at all possible don't stop at one rental home. 

I think my last set cost me combined $2800.

The reason I say so is that on average I received more calls, complaints, fixing, late rents, evictions etc. from this one multifamily than all my other 10+ single families combined.

@Kayla Uderitz My properties was a combination of broker connections and direct mail.

Buying your first one is scarier than your next 10 combined. 

If so, maybe I should do a combination - refinance the rental unit, take the balance of the cash out and pay down the primary address, then get a HELOC on the primary address? 

Every bank account, loan application, mail forwarding, utility payments, etc, etc. combined tells the story of where you live.