When property which has not actually been returned by anyone is assessed for taxes, the tax collector or tax commissioner shall issue an execution against the property as soon as it is assessed for the amount due and costs. The sheriff shall advertise the property for sale in the newspaper in which sheriff's sales are advertised once a week for four weeks before the day of sale. If the taxes are not paid by the day of the sale, the property shall be sold, but only if renting or hiring the property will not bring the requisite amount. Surplus from a sale after the payment of the taxes and costs shall be paid over to the county governing authority as a part of the educational fund, together with a statement of the property and account of sales, subject to the claim of the true owner within four years.