If it's a material defect, they have to tell you.

Somebody wanting to sue for you backing out of a bad deal or accusing you of selling them a property with defects like unknown termite damage).

That's always the best way to get the most money for a property.That suggests that either there's something major wrong - as others have said, not pulling permits, hidden major defects, title issues, etc.The other possibility is he financed with hard money and has a balloon payment bearing down on him.Before walking away, I'd have a conversation with the agent/daughter. 

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* Paint cannot be chipping, peeling, flaking or otherwise defective.
* Electrical outlets and switches must function properly.
* Windows must open, close and lock.
* Roofing cannot leak and must have at least two years of life remaining.
* Attics and crawl spaces must have vents and be free from damage.
* No active termite infestation.
* The property must be reasonably free from environmental hazards, odors and excessive noise.

Telltale cracks, old, poorly done renovations and patches, original construction defects, water damage...they are all information which helps me adjust my build plan if needed. 

Also, in private sales there is no requirement to disclose material latent defects so Buyer Beware.

Then the transaction from B to C (you) is a totally separate transaction with title insurance.Before you close the title company taking care of the transaction / or the attorney as they use both in St Louis will provide you with a preliminary title showing all the problems they can find with title - the middle buyer is not going to be able to close with clouded title unless their contract says that they will buy with title defects, in which case if they are assigning the contract to you, would have you taking over their original contract.In a double close however there are usually 2 separate contracts and you need to read the one you are a party to so you can see what you agreed to in regards to marketable title.

I suspect it was either damaged during installation or it's a manufacture defect.

<--(Check this)Have an intermittent outdoor unit fan issue and it will not cool properly.Have a defective (or improperly wired or wrong) Thermostat for the system and it will not cool properly.Not all techs are equally as good--or equally as honest.Good Luck!

The property came with some structural defects that require an investment to repair, but the necessary repairs will make the property more valuable and desirable in the long run, allowing for future opportunities to serve higher paying tenants.