It’s probably easier to just raise the rents to cover your utility costs or look into electric heat pumps.

Utilize your strength and go for it.

I'd just ask what condition the property is - if it's not turnkey then the 5% for capex, maintenance may be too low (and I agree with Cade that vacancy should be bumped up a bit too) - 8% is where I'd start with those three, being as conservative as I am.Who is paying utilities and associated costs? 

The quadplex seems like an ok deal, but is the apartment going to dictate my rents and what the tenants should expect to pay for utilities? 

I believe the best way to go about this would be to utilize the HELOC as your new checking account and sit all of your monthly income inside it to reduce principal, which in turn reduces the amount of interest you pay and basically reduces your monthly payment every single month.

Being that you're in the other unit, you'd be paying over $2,000/month yourself - NOT including taxes, utilities and capex. 

Account Closed yeah I've been selling a lot of fourplexes lately and they should all cash flow, even with appropriate numbers for vacancy, utilities, repairs, capital expenditures, and property management.

Keep in mind your holding costs also will include utilities and insurance (I assume you plan to carry insurance). 

Residents pay all utilities.

(After accounting for other expenses: utilities, appliance, extremes I am looking at a total of about $1,020/ Mo.).