Viessmann Flue Gas System Installation Instructions for Vitocrossal/Vitodens/Vitoladens

About this manual

This document provides installation instructions for contractors regarding the flue gas system compatible with Vitocrossal (type CU3), Vitodens, and Vitoladens boilers. It outlines safety protocols, general installation guidelines, and specific requirements for routing flues through ducts or as technical units. The guide emphasizes the need for competent personnel to perform installation, initial start-up, inspection, maintenance, and repairs.

What's inside

• Safety instructions
• General installation instructions
• Leak/soundness test
• System certification
• Statutory requirements
• Boiler Position
• Flue terminal position
• Flue termination position
• Horizontal flue system
• Vertical flue systems

Frequently asked questions

What is the maximum flue gas temperature for which these flues are approved?

The flues are approved for use with flue gas temperatures up to 120°C.

What pressure must be reached when testing a sealed pressurised flue inside a building?

Air must be pumped into the sealed flue until a pressure of 200 Pa has built.

What is the maximum acceptable CO2 concentration in combustion air for a sound balanced flue?

The flue pipe is deemed sound if the CO2 concentration is no higher than 0.2%.