Flue Vent Length Requirements; Multiple Boiler Installations (Vertical Termination); Multiple Boiler Installations (Horizontal Termination) - Viessmann Vitocrossal 300 CU3A Installation Instructions Manual

CU3A Venting Systems Installation
Flue Vent Termination Requirements
Single Pipe Venting (Room Air Dependent)
Multiple boiler installations (vertical flue termination)
When terminating the vertical vent pipes of multiple
Vitocrossal 300 CU3A boilers, a minimum clearance of
4 inches (100 mm) is required between the outside edges
of each vent pipe.
Multiple boiler installations (horizontal flue termination)
When terminating the horizontal vent pipes of multiple
Vitocrossal 300 CU3A boilers, a minimum clearance of
12 inches (305 mm) is required between the outside
edges of each vent pipe.
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