Raising Flue Gas Temperature; 11.5.1 Removing Heat Exchanger Baffles; 11.5.2 Removing Hot Gas Check Plates; 11.5.3 Increasing The Flue Gas Temperature Slightly - Buderus Logano G515 Installation And Service Instructions Manual

11
System start-up
11.5

Raising flue gas temperature

With a new boiler, the flue gas temperature when the boiler temperature
is 176 °F (80 °C) will be around 320 – 356 °F (160 – 180 °C),
depending on the boiler rating.
In two-stage operation the temperature of the flue gas is lower.
You can increase the flue gas temperature further by removing individual
hot gas check plates and hot gas baffle plates or combinations of these.
You should only consider modifying the hot gas check
plates as a last resort as once you have reduced the size
of the hot gas check plates you cannot change this back.
▶ Take the boiler out of operation in accordance with the operating
instructions.
You can increase the temperature of the flue gas by carrying out the
following measures.

11.5.1 Removing heat exchanger baffles

For boilers with 7 – 11 boiler sections (819 – 1,553 MBH or 240 –
455 kW) an increase of the flue gas temperature can be achieved
through pair-wise removal of the upper or lower flue gas baffles.

11.5.2 Removing hot gas check plates

You can significantly increase the flue gas temperature by removing the
hot gas check plates.
▶ Take the hexagon socket screws out of the hot gas check plates on
the left and right and remove the hot gas check plates ( Fig. 68, [1
and 2]).
2
Fig. 68 Position of hot gas check plates
36
1
720 42 23- 5.1o

11.5.3 Increasing the flue gas temperature slightly

▶ Take the hexagon socket screw ( Fig. 69, [3]) out of the hot gas
check plate on the left and right ( Fig. 69, [1 and 2]) and remove
the hot gas check plates.
▶ Place the hot gas check plate on the support with the channels
( Fig. 69, [1 and 2]) facing downwards. Knock off one segment of
the left and right hot gas check plate with a hammer.
▶ Screw the hot gas check plate back onto the front section with the
hexagon socket screws.
3
Fig. 69 Hot gas check plate
▶ If the flue gas temperature increases by an insufficient amount, the
second segment on the hot gas check plates can be broken off in the
same way, or all hot gas check plates can be removed as described
above.
1
2
720 42 23- .1o
Logano G515 – 6 720 647 208 (2014/09)