12
If you want to stop the boiler for a longer period then you MUST empty the burner tube
from glows to avoid a burn-back into the fuel store.
The risk of burn-back is varying from one fuel to the next. Wood chips are more likely to
cause back-burn than grains or pellets. The glows might due out by the selves, but you
cannot be sure, this happens
If the boiler is stopped e.g. during summer, then please open the combustion room
door to prevent moisture from condensing in boiler or chimney.
2.8 Bypass (flue temperature damper)
The very effective flue cooling in the boiler means that the flue is only 140 – 150 ºC by
100% load, when leaving the flue outlet. The flue temperature is closely connected to
the boiler output, means lower load = lower flue temp.
The handle on top of the boiler (the bypass) is used to adapt the flue temperature in
relation to boiler output. By fully opened damper only a part of the flue is passing the
flue cooler. By fully closed damper the flue is cooled to maximum (see fig 4)
Section 2 – Start up and normal use
If the boiler load is less than 40 – 50 %,
as is the case in large parts of the year,
you should open the bypass to increase
flue temperature, that the flue does not
condense on its way up through the
chimney. If in doubt about how to place
the damper, please consult your
installer.
(see section 2.6, pause)
20
40
60
80
80
100
120
140
100
160
180
200
220
Flue temp. °C
Open Bypass
Closed Bypass
Boiler load %
