Table of Contents
Advertisement
red
Other flame features:
a bright red flame indicates lack of secondary air and consequently the need to increase the
secondary air flow by opening the total air flow control fin (operated by the thermostatic valve);
a light yellow or short flame indicates excess of secondary air and the secondary air flow
must be decreased by closing the total air control fin, adjusting the thermostatic valve which
controls the fin;
a dull flame ("weak flame") indicates that the primary air flow must be increased; pull the axes of
the primary air control fin, thus opening the fin to do this;
smoke in flame indicates that the secondary air is lacking but that the intensity of volatile gases
and the release rate of tar have increased. For this reason, the primary air flow must be
decreased and the secondary air flow must be increased; close the primary air control fin by
pushing it to do this. The effect of this adjustment will be visible after at least 15 minute. Wait
patiently. The position of the axes must be changed in small steps because this adjustment is
very sensitive.
Optimal combustion can be obtained also by observing the conditions of the ceramic element positioned in
the boiler combustion chamber; the outer surface of the ash layer must be light grey, the amount of
deposited ashes must be low and there must be no black, unburnt particles (combustion residues are dark
specks).
The combustion process adjustment amount can be determined by monitoring the colour of the combustion
gases released from the chimney connected to the boiler. Dark combustion gases mean that the secondary
air is not sufficient and/or that the amount of fuel is not compliant (the content of humidity is higher than
required).
Boiler operation in stand-by mode
6.9.
If the heat output of the boiler is higher than needed, the temperature of the circulating water will be
increased and the set point of the boiler operating thermostat will be reached; in this case, the combustion
gas fan will be turned off, the boiler will switch to stand-by mode and the heat output of the boiler will be
further decreased. Air is naturally conveyed into the boiler in stand-by mode and oxidation of the
combustion residues in the fuel hopper chamber is guaranteed. Measurements indicate that in stand-by
mode, the heat output of the boiler is approximately 10% of the nominal heat output of the appliance. If the
temperature of the circulating water decreases, the combustion gas fan comes on and within a 3-5 minute
period the combustion process reaches nominal operating conditions and the boiler heat output is increased.
6.10. Boiler shutdown
The system is automatically shut down by not loading wood logs into the boiler combustion chamber,
waiting for the combustion process to end and then turning the "START" switch to the OFF position. Wait for
the boiler to cool down to ambient temperature and turn it off by means of the "POWER" main switch. You
are recommended to carefully remove deposited ash from the heat exchange surfaces of the boiler.
Start-up procedures
TECNIKA 28-35
USE AND INSTALLATION MANUAL
Technical dept. - All rights reserved - Reproduction prohibited
Chapter
6
page 43
Advertisement
Table of Contents
