The Viessmann 80mm Flue Gas Non‑Return Valve is a specialist safety component designed to prevent reverse flue gas flow within compatible Viessmann boiler systems. Installed within the flue system, this precision‑engineered valve ensures that combustion gases only travel in the intended direction, protecting the boiler and the property from potential backflow issues.Its robust, corrosion‑resistant construction ensures long‑term reliability, particularly in multi‑boiler installations or systems with shared flue routes where consistent directional control is essential. Compact, efficient, and engineered to Viessmann’s high standards, it offers a trusted solution for maintaining safe and compliant flue operation.

Key Features

• Prevents reverse gas flow
  Ensures safe one‑way flue gas movement, preventing backflow into the appliance.
• Designed for 80mm Viessmann flue systems
  Fully compatible with Viessmann’s 80mm flue accessories and components.
• Essential for multi‑boiler or shared flue configurations
  Helps maintain correct airflow and system pressure balance.
• Durable, corrosion‑resistant construction
  Engineered for long‑term performance in demanding flue environments.
• Compact inline design
  Easy to install within existing flue runs without disrupting layout.
• Improves overall system safety and compliance
  Supports safe operation of modern condensing boiler systems.

Technical Specifications

• Diameter:
  80mm flue system compatibility
• Function:
  One‑way valve preventing backflow of combustion gases
• Material:
  High‑quality, corrosion‑resistant components suitable for prolonged use
• Installation:
  Inline fitting within Viessmann 80mm flue routes
  (Check boiler/flue manuals for exact position requirements)
• Application:
  Enhances safety in single or multi‑boiler setups
  Supports correct draft and pressure conditions in shared or extended flue systems
• Compatibility:
  Viessmann boilers and flue accessories designed for 80mm systems