55
0*
Setting failure
- check parameter
D
(second digit must be
0
)
1!
Failure of inter-
nal communi-
cation bus
- short circuit in flat cable: replace flat cable
- water/condensation on display
- possibly external EMC contamination
1@
External inter-
lock
- The external interlock (terminals 10 and 14) open cir-
cuit : check external interlock or replace link between
terminals 10 and 14.
- Fuse F2 failed
1*
Flow tempera-
ture too high
Check:
- the waterflow,
ref. Par. 7.4.7
- system for trapped air
- sensors for resistance at set temperature,
see graph in
Fig. 22.
- if the boiler is full of water
1(
Return tempe-
rature too high
2$
Return temp >
flow temp
- Flow sensor badly installed
- Pump operating in wrong direction or flow and return
connections crossed
2*
Fan not run-
ning
- Fan or motor failed
- Supply and/or signal control cable – poor connections
or failed.
2(
Fan runs con-
tinuously or
speed signal
not correct
- Check control cable connections and for continuity
- Fan defective
- Flue draft conditions too high
3!
Temperature
sensor failure
Flow temperature sensor short circuit
3@
Return temperature sensor short short circuit
3$
Outside temperature sensor short short circuit
3^
Flow temperature sensor not connected or open circuit
3&
Return temperature sensor not connected or open circuit
4)
Setting failure
check parameter
D
(first digit must be
0
)
7&
Ionisation failu-
re during boiler
operation
After 4 restarts during 1 heat demand
- flue gas recirculation (internal/external)
- insufficient air flow – check fan or air inlet/flue outlet for
obstruction
- incorrect combustion.
