Learn More 0 Best Condensing Boilers | Boiler Replacement Cost Jun 00, 0000 · Most homeoweners spend $0,000 - 0,000 to install a condensing or a combi boiler. The price for the boiler itself can be as low as $0,000 and can reach $0,000 for a high-end Bosch Buderus SSB model with over 00% efficiency rating. Most condensing boilers fall in the range of $0,000-0,000 depending on the brand, efficiency rating, and capacity.Learn More 