Viessmann VEK, Service Instructions Manual

Page: 23 / 44

23
Troubleshooting
Diagnosis (burner control unit LMO14. ...)
(cont.)
Fault/
characteristics Flashing
code
red at
LMO14 Cause Remedy
Pump does
not supply oil 2× Shut−off valves closed at
filter or in oil pipe Open valves
2× Filter blocked Clean filter (pre−filter
and pump filter) or
replace if required
2× Clutch between motor
and pump faulty Replace clutch
2× Leak in suction line or
filter cup Tighten connections.
Check oil pipes and
connections for leaks
and seal as required.
2× Oil flow and return
hoses interchanged Connect correctly acc. to
instructions on pump
2× Vacuum in suction line
too high (higher than
0.35bar) Check size of oil pipe
cross−section.
Replace filter. Check
external fuel oil valve.
2× External fuel oil valve
faulty Check and, if necessary,
replace external fuel oil
valve
Burner starts,
b
il
2× Solenoid coil faulty Replace solenoid coil
,
but no oil
injected
2× Oil pump faulty Replace oil pump
injected
2× Nozzle blocked Replace nozzle
Extraneous
light during
pre purge 4× Oil pump solenoid valve
fails to close Replace oil pump
pre−purge
phase
4× Flame monitor faulty Replace flame monitor
4× Ignition electrodes
poorly adjusted or worn Check ignition
electrodes and replace if
necessary
5692589GB