Checking The Oxygen Control System - Viessmann Vitoflex 300-RF series Service And Maintenance Instructions

Troubleshooting
Checking Oxygen Control System
A check of the oxygen control is carried out in case of incomplete combustion, dark smoke escaping the chimney or
performance problems.
Clean the oxygen sensor
Install the oxygen sensor
24
oxygen
Checking the
control system
Visual check of wiring
o display
xygen
with fresh air
between
20% - 21%
Yes
so it is leak tight
Check the boiler

Check that all electrical lines are
permanently connected

Clean the outside of the oxygen
sensor using a wire brush

Hold the oxygen sensor downwards
and gently tap out with the bristles of
the wire brush until no more dirt falls
out of the probe
No

Balance the oxygen sensor (see
section on balancing the oxygen
sensor)

Set the heating system to cleaning

Check the leak tightness of the
installation with the flue

Close the doors of the exhaust gas
collector and boiler door airtight
(check with the flue)

Pneumatic cleaning system is
operational and leak tight
Vitoflex 300-RF Service & Maintenance