12
S
ECONDARY AIR ADJUSTMENT
F
LAME
C
AUSE
A
DJUSTMENT
Red flame with black swirling.
Secondary air is not enough for
burning. The stack discharges
black or dark smoke.
Add secondary air.
Yellow white flame.
Good air distribution. The
stack discharges light grey
smoke.
No need to adjust burning.
Dazzling white flame.
Too much secondary air. The
stack discharges white smoke.
Reduce the amount of secon-
dary air.
Maintenance
•
Regularly check that the system is filled
with water; if you have to add water con-
stantly, then the system is leaking. Con-
stantly adding fresh water causes corro-
sion to the heating system since fresh wa-
ter contains air (oxygen).
•
The hot system pressure should be lower
than 1.5 bar and the cold system pressure
higher than 0.5 bar ( 1.5 bar safety relief).
The water volume varies as the tempera-
ture, i.e. the higher the temperature, the
higher the volume and the pressure. The
expansion tank serves to smooth such vo-
lume variations.
•
Check the pre-pressure of the expansion
tank at several years' intervals.
•
Check the safety relief valves at least twi-
ce a year by rotating the knob/lever in or-
der to prevent sticking. Add water to the
system after the check.
•
While burning firewood take care to en-
sure that the boiler water temperature is
always higher than the flue gas due point
i.e. at least 70 ºC and the flue gas tem-
perature is at least 150 ºC in order to pre-
vent corrosion.
•
Remove ashes from the furnace and the
firing throat as required.
