Heating System Faults - Viessmann Vitoflex 300-RF series Service And Maintenance Instructions

Troubleshooting

Heating System Faults

Fault Text displayed
No.
01 Excess temperature
(red light at F1, F2,
F3)
03-17 Interruption or
short-circuit, sensor
09 Oxygen sensor
(red light at F3)
18 Permanent code
(red light at F3)
19 Repeat heating up
(red light at F3)
20 Water level in
extinguishing
Water container
(red light at F3)
25 Light barrier, ember
monitoring system
(red light at F3)
26 Light barrier,
feed auger
(red light at F3)
96 Feed auger pipe
too hot
81-93 BUS error, no
connection to the
(red light at F3)
53-54 Extraction system
... silo door open
(red light at F4)
26
Indicator Possible cause
Fixed high limit - Incorrect setting in the
N21 control module
- Defective component (pump
or valve)
- Sudden drop in output to zero.
The feed auger then has to be
emptied. The heat produced
by this can result in excess
temperature. Activate the
function "Dissipate excess
heat"
- Sensor . . . - Damaged sensor connection line
- Indicator defective
- Oxygen sensor - Indicator very soiled
in the flue - Indicator defective
gas pipe - Error in the electronics
- Operating hours - Permanent code has not been
lapsed before the entered
permanent code
has been entered
- Exhaust gas - Fuel too moist
temperature - Oxygen sensor imprecise
sensor - Igniter defective
- Oxygen sensor - The combustion chamber
filling time is too short
- Level float switch - Not enough water in the
in extinguishing extinguishing water container
water container
- Light barrier for - Sight glass soiled;
ember monitoring deposits of ash in the openings
system - Defective indicator
- Light barrier in - Light barrier soiled
the metering - Clogging in the metering
container for the container
feed auger
- Temperature - Power failure
sensor on the - Consequent malfunction
feed auger caused by excess temperature
- Light barriers for ember
monitoring system soiled
- Data transmission - Bus connection interrupted
line for the bus
connection
- Limit switch for - Silo door open
silo door
Vitoflex 300-RF Service & Maintenance
Check / remedy
- Why could the heat not be
dissipated?
- Check the boiler pump and
mixing valve
- Activate the function
"Dissipate excess heat"
- Unscrew the protective cap on
the fixed high limit and press
the reset button (not
possible until the boiler
temperature is less than 158°F
(70°C) and press OK
Call a qualified electrician
- Readjust oxygen sensor
- Acknowledge with OK
- Call Viessmann
- Use suitable, dry fuel
- Readjust oxygen sensor.
- Replace ignition device
- Readjust combustion chamber
- Acknowledge with OK
- Fill extinguishing water container
- Acknowledge with OK
- Remove and clean sight glasses
on both sides
- Remove dust and ash deposit
from the openings
- Refer to the section,
"Cleaning"
- Acknowledge with OK
- Clean light barrier
- Remove clogging
- Acknowledge with OK
- Call a qualified electrician
- Check light barriers for embers
- Acknowledge with OK
- Check plug connections
- Replace data transmission line
- Call Viessmann
- Check and close silo door
- Acknowledge with OK