Flue Gas System Connections; Flue Size; Connection To The Flue Gas Pipe - DeDietrich GTU C 330 Installation And Service Manual

4.7 Flue gas system connections

GTU C 330 condensing boilers are characterised by the following
points :
- High performance, leading to the acquisition of very low flue gas
temperatures (< 65 °C).
- Boiler with a positive pressure at the condenser nozzle (see:
Technical characteristics, page 9).
4.7.1

Flue size

Refer to applicable regulations while determining the size of the flue.
4.7.2

Connection to the flue gas pipe

Horizontal flue gas conduits must be fitted with a minimum gradient
of 3° to the boiler to allow the condensates which form in the chimney
and the conduits to flow to the condenser.
The connection shall be removable, and offer minimum load losses,
i.e. it must be as short as possible with no sudden change in section.
Its diameter shall always be at least equal to that of the boiler outlet,
i.e.:
Ø 160 mm : for 4 to 6 sections
Ø 200 mm : for 7 to 9 sections
Fit a gastight measurement outlet (diameterØ 10 mm) to the flue gas
connection between the boiler and the condenser to adjust the burner
(Checking the combustion in the boiler).
07/04/2009 - 300016152-001-C
To protect the conduits and the chimney:
- Use conduits which allow no flue gas leakage
- Use conduits resistant to acidic condensates (PPs).
Boiler with a positive pressure at the condenser nozzle (see:
Technical characteristics, page 9).
GTU C 330
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