approach to negotiation regarding boiler

[Long Yang]

Hi, we are about to go under contract for a 8 unit building. The seller says the boiler is three years old but 1) the seller doesn't have manufacturer warranty or 2) he can't find the warranty information. Should we just wait for the inspection period to see the boiler condition? And make requests such as seller pay for home warranty, credit purchase price, or do the repairs based on the finding? Or should we negotiate something like "seller pay for any boiler repairs above $1000 in the first two years" into the contract first? 

 Thank you biggerpockets community!