Question: how much does it cost to replace an old oil boiler?
Answer: Cost Factors The oil boiler will also need to be removed at a cost of $500-$3,000, and a chimney liner will need to be installed ($1,000). A new boiler cost, including installation, averages $7,000 (but the cost can range between $4,000-$7,500). Most homeowners struggle with repairing or replacing their gas boilers.