It is in a class B neighborhood and all the repairs are done on it.

You will never find 2% rule in hawaii, its more like .5% unless you are looking at vacation rentals.  50% rule is again a guideline for quick analysis, when you actually start crunching the numbers this rule goes out the window.  70% rule is for after repair value, not what a fixer upper is listed for. 

and have run into a snag.The HVAC needs some repair/maintenance work, and we aren't getting heat into the building.

You might think they should have known better, but there is zero reason for them to have thought that these couldn't be flushed.In my opinion, this repair is on you. 

Other things to factor in:-rehab costs-PMI-closing costs-for vacancies, repairs, cap-ex: I typically do 5%/each, 15% total (some may argue to be more conservative on your analysis)As far as the cap rate, my understanding is the cap rate is more so for properties with >4 units.

But if they are seeking to hold a property for any length of time and want their cash investment back there are some important rules to understand with conventional loan:If you buy a property with cash (or with a HELOC) you can receive a cash out loan on Day 1.There is not a 6 month waiting period with receiving a cash out loan if you purchased a home with cash or with a HELOCBUT you will be limited to the amount of....Your purchase price + closing costs (costs when you purchased the home)OR75% of the “After Repair Value”...WHICHEVER IS THE LOWER AMOUNT (super important)These rules are important to understand so here are two examples:Example 1: If you purchased a home with $50k of cash, and put $30k of renovations into the loan, and the home was worth $100k. 75% is $75k and $50k is your purchaseprice.

We don't have $120k cash, and the home needs some minor repairs before it is lendable (probably around $7k), and it's a foreclosure and they will MOST LIKELY not do any repairs before closing (they're looking for cash buyers obviously). 

And those 3 rental properties , one is doing fine , the second one the septic failed and you need a advanced system for $20K and the last rental the tenants didnt pay and you have to evict and repair $ 10k of damage ,Now , you were saying something about paying yourself ?  

In a few months, a dog could destroy cupboard corners or doors that require LOTS of repair $$, and a long vacancy, and the tenant will not understand what it will cost me, so there could be a big disagreement over the withheld deposit.

I gave my contractor a deposit in December and final payment in January for a large structural repair job on a property that is partially personal (I live in one room) and partially business (my LLC) as a vacation rental.Now I need to send him a 1099 and send the IRS a 1096 (late on both of these, I recently found out), and figure out which tax year to apply the payments.