Diagnostics - Viessmann MatriX radiant burner Service Instructions Manual

Diagnostics

Faults with fault display at the display and programming unit
General process error
Fault System
code characteristics
20 Fan does not stop
during the air
pressure switch
idle state check
Air pressure switch
contact does not
open
21 Air pressure switch
does not signal air
pressure, fan does
not run
Fan does not run
22 Gas governor does
not signal gas
pressure
25
No flame after
safety time, y
ionisation flame ionisation flame
monitor signals no
flame
Cause
Wind influence on
fan
Air pressure switch
faulty
Air pressure switch
faulty
Fan faulty, cables
faulty or broken
Gas shut−off valve
closed, gas
governor faulty
Ionisation electrode
incorrectly adjusted
Ignition electrodes
incorrectly adjusted
Insulation body of
ignition electrodes
cracked
Incorrect gas type
selected
Gas combination
valve does not
open
Combustion
characteristics not
ideal
Parameter set
incorrectly adjusted
Troubleshooting
Remedy
Check flue gas draught
(chimney)
Replace air pressure
switch
Replace air pressure
switch
Check cables and replace
fan, if required
Open gas shut−off valve,
check gas supply
pressure and clean gas
filter, if necessary
Adjust ionisation
electrode (see page 15)
Adjust ignition
electrodes (see page 15)
Replace ignition
electrodes
Adjust gas type (see
page 7)
Check gas combination
valve and replace it, if
required
Adjust burner (see
page 11 and 12)
Adjust parameter set
(see page 23 and 24)
27