Fusion Boiler Benefits - No flue required - No fumes and no risk of explosion - 100% efficient - Economic running costs - Virtually silent in operation - Can provide central heating only or central heating & hot water - Can be used for under floor heating - No annual safety certificate required - 24 hour controllability - No maintenance required - Multiple fail-safes fitted in unit - LED indicators show status of operation - Preferential electricity tariffs available For boiler replacements whereby the current system has an expansion vessel installed external to the boiler The Fusion Slimline Electric Boiler is the ideal replacement. The Slimline model is identical to the standard Fusion Boiler with the exception of the overall dimensions and excludes the expansion vessel.