20
5603 880 - 03
Vitoflex 300-RF Service & Maintenance
Performance Problems
The boiler does not provide its original performance.
Performance
problems
Boiler temp.
ACTUAL <
Boiler temp.
TARGET
Exhaust
gas temp.
ACTUAL <
Exhaust gas
temp. limit
value
1 Check settings
2 Heat cannot be dissipated
3 Check the function of the boiler
pump and the 3-way mixing valve
F3 parameter
control menu
Boiler
re-establishes
its performance
Fault rectified
Fault rectified
Fault rectified
Fault rectified
Fault rectified
Fault rectified
1 Clean heat exchanger
F3 parameter
control menu
Boiler
re-establishes
its performance
Boiler
re-establishes
its performance
Boiler
re-establishes
its performance
Boiler
reestablishes
its performance
Boiler
re-establishes
its performance
Residual oxygen
ACTUAL
Residual oxygen
TARGET
Fuel < W35
Open
primary
air vent
Check that
grate vents
move
smoothly
Contact Viessmann
1 Clean grate
2 Clean all four sight glasses and
pipes of the ember monitoring
system light barrier
3 Check the position of the light
barrier
F3 parameter
control menu
1 Use proper fuel
2 Close recirculation temporarily
3 Open ash chamber door that
is closer to the feed auger by
2” (50 mm) temporarily
1 Check air vent moves smoothly
2 Compare opening angle on the
operating
console
3 Check electrical connections
1 Clean grate vents of cinder
coatings
2 Remove impurities
Yes
No
No
No
No
No
No
No
No
No
No
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Troubleshooting