4.21 BURNER MAINTENANCE
CLEANING THE IONISATION SENSOR ELECTRODE
Fault No. 2 indicates that the ionisation electrode is sooty, faulty or shorted. Soot build-up on the sensor is not as
common and it is, without exception, the result of poor combustion, and always requires cleaning the burner as
well. The electrode can be cleaned without removing it after the burner is removed. For cleaning you can use e.g.
rubbing alcohol-based cleaning products (car windshield washer fluid, etc.). It is important that the insulation of the
electrode is clean so that current does not leak, which disrupts the functioning of the heater. Also, the electrode
wire should not touch the burner.
The tip of the ionisation sensor should be placed according to the dimensions in the figure. You can cut a piece of
cardboard for measuring, for example. If necessary, you can bend the sensor wire. However, be careful not to
break the insulation. Small cracks will not cause the electrode to malfunction.
.
.
1. Disconnect the power so that the circuit board is
powerless.
2. Remove the control panel of the heater. Disconnect the
wire connectors of the circuit card.
3. Disconnect the fuel inlet line (2).
4. Open the burner compartment cover (3 screws, force the
top of the cover open from the protrusions)
5. Remove the glow plug (1) and its
mounting plate
6. Remove the burner support spring and the burner (8). If
you are unable to remove the burner, use a hammer and a
suitable piece of wood, see picture. Remove the topmost
centering plate of the spring (11) first in order to remove the
burner cylinder without damaging the ionisation sensor
(10).
7. Open the burner hat (5) locking (4) e.g. with a
screwdriver. Push the screwdriver between the cylinder and
the lower ring so that the lower ring can pass the locking
claw. Turn the screwdriver and lift the hat at the same time
in order to lift the lower ring of the hat over the locking.
8. Clean the burner e.g. with an old toothbrush. The soot at
the bottom can be removed with a screwdriver. Use dish
soap and water for cleaning.
9. If required, replace the base fabric (6), which is held in
place by the locking spring (7).
10.
Assemble the burner in the reverse order. Ensure
that the ionisation sensor tip is positioned according to the
figure and that the burner is in the right position. Use a glow
plug to centre the burner during assembly. Ensure before
closing the burner compartment that the distance between
the outer corner of the heat exchanger and the middle of
the fuel inlet pipe is 48 mm. The inlet pipe is now aligned
with the hole.
