Sure he can sell you the home. The question is whether or not you qualify to buy. If you do and your siblings do not object to the sale then you will be good. Depending on your age and the equity position in the home you may be able to do a reverse mortgage to purchase the home. Wells Fargo is one of the banks that offer this program and I used it to help a person purchase a home. Best
Get pre-approved using your current SS income. Get a payoff from his lender to see exactly how much you need payoff. Ask the lender for a good faith estimate. You will be responsible for all the bills; real estate taxes and homeowners insurance and utilities. Assuming you are qualified ask your lender what the minimum gift of equity your Dad you need to give you. If it is for example 25%, then he sells the property to you for $65,000 with $16,250 gift and 3,750 left over to pay for the costs. Your loan in this case would be $48,750 this is just an example check with your lender. There may be some gift tax check with a tax professional.