Replacing functioning but old HVAC/heater at closing

[Nikhil Garg]

I'm in the process of closing my first rental property. Both water heater and heat pump are around 18 years old though are functioning normally right now. It appears that they are going to break down in next couple years (but I may be wrong). Seller recently did a professional tune-up to AC and has made it clear that they are not going to make any more repairs (they repaired a bunch of things very recently). So I'm considering three choices: 

1) just let it be for now and replace it when it finally breaks down 

2) replace it now but request seller to include this in closing costs so that I can finance the cost. 

3) just replace it after closing myself (or maybe in fall when prices are a bit cheaper)

Little bit about my situation - I'm not tight on cash so can fully pay it out of my pocket now or later. Also, this property is outside state and I'd prefer to keep ongoing maintenance after getting tenants to be as little as possible. 

Any advice?