Vaillant Boiler Section 240kW 0020058851

The Vaillant 0020058851 is a boiler section rated at 240kW, forming part of the heat exchanger assembly on Ecocraft VKK 2406/3-E appliances. It is the individual cast section through which the heating water passes, and it is replaced when a section fails through corrosion, cracking or leakage. The part number identifies the section by output rating, so it must be matched to the appliance it is being fitted to.

• Water weeping or tracking from the section joint or body
• Visible corrosion, pitting or scale build-up on the section surface
• A hairline crack in the casting, often found during pressure testing
• Kettling or localised boiling noises from the heat exchanger
• Reduced heat output or uneven temperature across the sections

• Confirm the appliance model and variant from the data plate, as the section rating must match the boiler
• Check how many sections the appliance requires, as more than one may need replacing
• Inspect the section seals and gaskets, as these are normally renewed when a section is disturbed
• Check the system water quality and treatment history before reassembly