My plan is to use my HELOC from my current primary residence as the down payment.

Look at the values of your 2 properties, consider any outstanding debt, calculate what your payment might look like on a cash out refi, compare that to current or potential rents.

I know very little about legal precedent but I'd expect the major meter manufactures (selling into the utility space) to be well incentived to challenge these items best they can, and they have money.Here are the issues, and the reasons that the difference between an air forced system and a boiler/hydronic system are not meaningful for this discussion (ie efficacy issues of sub metering exist for either when method of measurement is measuring heat at point of delivery):In either case, the blower (or pump for a boiler) is the method of 'moving' either air (central air) or water/glycol or equivalent (boiler etc). 

My question is "for anyone with this particular experience" Is it a far fetched idea to do a cash out refi on house "A" to payoff some personal debt and large payment on house "B" to knock down the principal?

If rates do go down significantly, it will be more of a sign of economic instability.I recommend continuing to save monies until you come up with enough for a decent down payment.

. - We almost feel sorry for the foolish/naive DIY landlord that inevitably falls for their sob story and accepts them.We have had 2-3 that have gone through our process and so we accepted their multi-month payment.

The biggest downsides are that they usually have higher rates and require larger down payments.

Down payment assistance/ a VC that partners with first time home buyers to provide a pathway to home ownership would be a welcome addition to the industry!  

Net Income: 100k~ depending on overtime workedHere is a breakdown of the potential property we would be looking at buying as a long term investment. 3 Bedroom, 1 Bath, 1000sqft, attach single car garage, fully fenced property, needs no work and would be in a state of immediate ready to rent.Purchase Price: $289,90020% Down payment: $57,980Mortgage Rate: 4.5% Amortization: 25 YearsProperty Tax: $3185 annuallyBi-weekly Mortgage Payment: $592Rental Details:Monthly Rent: $2600Mortgage: -$1184/monthProperty Manager: -$260/monthLandlord Insurance: -$105/monthProperty Tax: -$265/month15% Put Away: -$390Leftover: $396Does something like this make sense to jump on?

The mortgage payment is already high and my life circumstances have changed, making the payment even more of a stretch (not impossible, but definitely above the recommended percentage of take home pay).I am considering selling the first property next year (which has about $200K in equity) to do a mortgage recast on the primary and get my payment to something more reasonable.