Viessmann Vitogas 050 Rs Series Installation & Service Manual page 16

Ionization
electrode
Fig. 21
Pilot burner assembly – electrode settings
a) To remove the pilot assembly, release the ground
wire at the ground screw on the pilot burner, detach
the lead at the ionization probe and pull the lead at
the spark electrode. Disconnect pilot tube at the
pilot burner connection and remove the three nuts
M6 securing the mounting plate assembly to the
combustion chamber cover plate.
b) Inspect pilot burner, ionization probe and spark
electrode, making sure that they are in a sound and
clean condition. In particular check that ignition
electrode is clean and undamaged, and that the
spark gap is 2-3 mm, ionization and ignition leads
are not broken, chafed or burnt. Clean the pilot
orifice, do not broach out with wire (see Fig. 21).
c) Reassemble the pilot and refit onto the combustion
chamber cover plate in reverse order to that above
(see Fig. 22). Pilot burner should be removed when
cleaning heat exchanger to prevent debris from
blocking pilot orifice.
8.5 Water damage
Any electrical part or any gas control that has been under
water cannot be reused but must be replaced. Mechanical
parts that have been under water must be inspected for
suitability by a boiler technician prior to reuse.
16
Ignition electrode
2-3mm
16mm
Ground screw
Ionization
electrode
Pilot
burner
Ignition
electrode
(always on
bottom)
Note: Pilot is shown
on left side.
Standard gas train
requires pilot to be
mounted on right
side. See Fig. 11 and
Fig. 23A.
Fig. 22
Pilot burner installed
8.6 Burner damage
Do not allow drywall dust to accumulate in burners.
Assemble boiler after all drywall work has been
completed.
8.7 Freezing damage
Boiler and system must be protected from damage
caused by expansion of freezing water.
Protect boiler and system from freezing by using a
glycol mixture as described in section 4.3. Propylene
glycol mixtures with a corrosion inhibitor are frequently
used. Consult a reputable water treatment specialist.
If system is subject to freezing temperatures and is not
filled with antifreeze for protection, the system including
the boiler must be drained of water. Valve before
automatic feed valve (if installed) must be closed; any
other valves, air vents and drain valves must stay open.
44±2