Viessmann MatriX radiant burner, Service Instructions Manual

Page: 27 / 48

27
Troubleshooting
Diagnostics
Faults with fault display at the display and programming unit
General process error
Fault
code System
characteristics Cause Remedy
20 Fan does not stop
during the air
pressure switch
idle state check Wind influence on
fan Check flue gas draught
(chimney)
Air pressure switch
contact does not
open Air pressure switch
faulty Replace air pressure
switch
21 Air pressure switch
does not signal air
pressure, fan does
not run Air pressure switch
faulty Replace air pressure
switch
Fan does not run Fan faulty, cables
faulty or broken Check cables and replace
fan, if required
22 Gas governor does
not signal gas
pressure Gas shut−off valve
closed, gas
governor faulty Open gas shut−off valve,
check gas supply
pressure and clean gas
filter, if necessary
25
No flame after
safety time,
ionisation flame
Ionisation electrode
incorrectly adjusted Adjust ionisation
electrode (see page15)
y
ionisation flame
monitor signals no
flame
Ignition electrodes
incorrectly adjusted Adjust ignition
electrodes (see page15)
Insulation body of
ignition electrodes
cracked Replace ignition
electrodes
Incorrect gas type
selected Adjust gas type (see
page7)
Gas combination
valve does not
open Check gas combination
valve and replace it, if
required
Combustion
characteristics not
ideal Adjust burner (see
page11 and 12)
Parameter set
incorrectly adjusted Adjust parameter set
(see page23 and 24)
5692541 GB