What to ask for to check concrete proof of roof age, HVAC age

[Eunice L.]

Hi everyone! I am an out of state investor and I would love your advice on the following question. When you talk to a seller and they tell you that the roof or the HVAC is 3 years old or 5 years old etc..what do you ask for in terms of concrete proof? In the past when I was dealing with a trusted seller/company, I took their word for it and it worked out ok but going forward, I'd like some kind of concrete proof to be safe. Thank you!