The Worcester 87290001670 Seal Outer 125 mm is a genuine replacement sealing component designed to provide an airtight connection around a 125 mm flue or duct interface on your boiler. This outer seal helps prevent combustion gases or external air from leaking at critical flue joints, supporting safe flue gas evacuation, correct draft conditions and compliance with installation standards. A worn, compressed or damaged seal can lead to performance issues, noise, moisture ingress or fault lockouts, so replacing it with the correct OEM seal is important for reliable operation.

This 125 mm outer seal is compatible with Worcester and Worcester Bosch boilers that specify part number 87290001670 in their technical documentation and flue assemblies. To ensure correct fitment and dependable sealing performance, always verify the part number on your existing seal or consult your boiler’s service information before installation, as flue sealing components can vary in diameter and profile between models.

Supplied ready for direct replacement, the 87290001670 Seal Outer 125 mm installs around the appropriate flue joint when fitted by a qualified engineer. Choosing this genuine Worcester Bosch component helps restore proper flue sealing, supports safe combustion gas evacuation and contributes to consistent, trouble-free heating system performance.