58
Flex Fuel Owner’s Manual
March 2011
FGT-drop or AR too high! Fan lag!
The flue gas temperature during the “Start phase!” or in “Pellets mode!” has noticeably dropped or the
measured air factor was noticeably high.
Possible reasons for these noticeable effects could be:
• The firebox door or ash door was opened during the “Start phase!” or in “Pellets mode!” without
deactivating the “Flue gas and air factor monitoring” function
.
• The pellet hopper is empty. Check whether there are sufficient pellets.
• The ash chamber or flue pipe is full of ash. Switch off and clean the furnace as soon as operating
status “Boiler is switched off!” is displayed.
• The pellets insert is covered with ash or foreign objects and should be cleaned. Switch off the furnace
and wait until operating status “Boiler is switched off!” is displayed. Then clean the pellets insert.
The furnace completes “Pellets mode!” by initiating “Fan lag!”. Fan lag ends when the flue gas
temperature falls below the factory default switch-off threshold and the run-on time has elapsed. The
furnace then switches to standby mode (“Availability!”) and automatically restarts when a heating circuit
demand is present.
Flue gas temperature too low! Fan lag!
In automatic mode (pellets) the flue gas temperature has not exceeded a necessary threshold or has
fallen below the threshold for a long time. The furnace turns off after a fan lag. Wait until the lag period
expires (the duration is system dependent and varies between 10 and 40 minutes). At the end of this lag,
an error message appears on the display:
The most probable cause of this error message may be a faulty air supply. Wait until the furnace has
cooled down and is switched off. Then clean the firebox, primary air deflectors, insert, ash chamber and
the flue pipe. Press the control knob to restart the furnace.
FLUEGASTEMPERATURE TOO LOW!
Wait till the boiler is
cooled down! Please clean
the combustion chamber, the
boiler plate, the flue pipe
and switch the boiler on
again!
Boiler temperature: XXºF
Flue gas temperature: XXºF
Air factor X.XX
13: Pellets Auto Control
