Marissa, you need to speak with the bank to find out what was required by them to sign off on the loan in regards to the boiler. If the FHA appraiser who noted the boiler was in need of repair was only required to come back to make sure the boiler was operational only by the bank, you'll have to do some detective work. The appraisal should have a n addendum saying they returned and the boiler was operational, if not they could be liable. Yo are entitled to a copy of the appraisal because you paid for it. If the appraiser didnt come back, they may be liable for the work that needs to be done. If the realtor did the work themselves and they are not qualified to do it , they may be liable.
If a repairman came in to do the work, they should make good on they original repair, but they may have also noted the boiler was in need of repair as well. If this is the case you to know who knew this. Try to find out who did the repair and speak with them.