Viessmann VITOFLEX 300-UF Operating Instructions Manual page 33

Adjusting the ash removal
The amount of ash in the combustion chamber
depends on the ash content of the fuel. The ash is
automatically removed from the boiler by means of a
moving grate. The intervals at which the grate is
moved can be adjusted to individual requirements. The
ash is discharged automatically via the ash removal
system.
The ash removal cycle is matched to the relevant fuel
type during commissioning. Check the pause times of
the ash removal cycle during operation. The Boiler
technician or suitably trained persons must then adjust
the times to suit the relevant fuel.
Visual inspection of combustion
During operation, the control unit controls, regulates
and monitors all components and system parts auto-
matically.
Caution
Risk of burns due to hot machine components
Only touch handles and identified parts.
Never touch sight glasses or their retainers.
These components are connected directly to the
combustion chamber.
Unjamming the ash removal screw conveyor
Caution
Risk of crushing by and entanglement in the ash
removal screw conveyor
Never reach in through the maintenance cover.
Note
Wear personal protective equipment.
Always wear a face mask when handling ash or slag.
Requirements:
The system is switched off.
The firebed is completely burned down. Check the fire-
bed through the sight glass.
1. At the programming unit, switch to manual mode
under "Fuel" – "Ash removal".
2. Warning
There is a risk of deflagration when the com-
bustion chamber door is opened. Poking
around in the firebed leads to oxygenation,
which can produce a flash. Both can result in
severe burns.
Never open the combustion chamber door
during operation.
Before opening the combustion chamber
door, ensure that you are standing in a safe
place.
Never poke around in the firebed.
When setting the ash removal cycles, observe the fol-
lowing principle:
Long pause time between ash removal events
■
Small fragments may break away from the refractory
concrete in the combustion chamber as a result of nor-
mal wear. These concrete fragments are removed by
the ash removal system. The breaking away of small
concrete fragments has no negative impact on the
service life of the combustion chamber.
Check flames in the combustion chamber through the
sight glass.
The ideal flame is yellow to light yellow. This indicates
normal combustion in which the fuel burns cleanly.
3. At the programming unit, alternately tap on
"Clockwise" and "A-clockwise" rotation.
The ash removal screw conveyor runs forwards
and backwards alternately. This action will unjam
the ash removal screw conveyor.
4. Stop the movement of the ash removal screw con-
veyor.
The ash removal screw conveyor comes to a halt.
5. Open the combustion chamber door.
6. Caution
Hot ash and slag may result in burns.
Wear protective gloves when handling ash
and slag.
Remove large bits of slag with a poker or similar.
7. Close the combustion chamber door.
8. On the programming unit, switch back to automatic
mode.
The ash removal screw conveyor is now unjam-
med.
What to do if...
33