Your obligation is to tell them their is no fix and that if they like they can pay to replace it with a new one.You could also buy a inexpensive one on sale and install it next spring if you are really generous.

How long will it take to fix / get online.

@Daniel Brown If I was you I would let her know you are interested in REI so much that you would get the place rent ready ( She pays material your labor is free) "take over" as property management or something to that effect, Earn a little cash, learn from her and get on the job training.  

The good news is, this is very easy to fix.

I can typically get those smaller items fixed for the price of the service call or even lower and its not worth the hassle.If you are hoping to get the HVAC replaced or other appliances by them, it might work out unless it takes few more years and by then, you already spend that money on the home warranty and service call fees and they might not even cover the whole thing once it comes to replacing.They are here to make money and they will go out of their way to replace parts before replacing the entire item.

or fix up my camp to sell or rent?

It costs $650 for an investment property and the rest (deductibles, limits, etc are fixed). 

I could also do a HELOC at 5% (for about $150K) or get a construction loan at 6% and convert to fixed later. 

We will also be happy to provide color commentary on the project based on our on-site tours and conversations with the park manager and local stakeholders.Property Highlights:Price: $700,000Total Pads: 75 (53 occupied)Park Owned Homes: 5Seller Financing Available: 65% LTV, 8% Fixed Rate, Interest Only Payments, 5 Year TermAverage Lot Rent: $225 (~10-15% below market)Utilities: Water Well / Septic (City water/sewer line runs in front of property.

You'll then need to apply for the Certificate of Occupancy, pay the fee, and then wait for the inspector to come out and tell you what needs to be fixed.