Buderus 500 - 24/C, Servicing Manual

Page: 19 / 80

Symptoms 5
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Servicing manual Gas condensing boiler Buderus 500-24/S, 500-24/C and 500-28/C • Issued 02/2006 19
C [2p]
Fault:
The flow sensor has detected a temperature increase, in
the heating system water, of over 5 °C/sec.
No
1)
box 27
C [3a]
Fault:
The tacho signal from the fan has failed during the
operating phase.
No
1)
box 29
?3l]
Fault:
The tacho signal from the fan is not present during the pre-
operative or operating phase.
Yes
2)
No heating operation and no hot water. box 29
?3l]
Fault:
No current of air after a certain time.
Yes
2)
No heating operation and no hot water. box 30
?3y]
Fault:
The fan runs too slowly or too fast.
Yes
2)
No heating operation and no hot water. box 31
?4a]
Fault:
The flow sensor and safety sensor have detected a
CH flow temperature of over 105 °C.
Yes
2)
No heating operation and no hot water. box 32
?4e]
Fault:
The sensor test has failed.
Yes
2)
No heating operation and no hot water. box 33
?4l]
Fault:
The contacts of the flow sensor and safety sensor are
shorted to each other, or there is a short-circuit to earth
(ground), or the flow or safety sensor has detected a
CH flow temperature of above 130 °C.
Yes
2)
No heating operation and no hot water. box 34
?4p]
Fault:
The contacts of the flow sensor or safety sensor are
broken.
Yes
2)
No heating operation and no hot water. box 35
C [6a]
Fault:
During the ignition phase, the system has detected an
insufficient ionisation current.
No
1)
box 36
?6a]
Fault:
After four startup attempts, the system has detected an
insufficient ionisation current.
Yes
2)
No heating operation and no hot water. box 36
:6c]
Fault:
The system has detected an ionisation current before
burner startup.
Yes
2)
No heating operation and no hot water. box 37
?6c]
Fault:
An ionisation current has been measured as soon as the
burner shuts down.
Yes
2)
No heating operation and no hot water. box 38
C [6l]
Fault:
The flame goes out during the operating phase.
No
1)
?7c]
Fault:
The power supply was shut off during a crucial breakdown.
Yes
2)
No heating operation and no hot water. box 39
!88|
Operating phase:
Display test during startup phase:
The code is displayed for a maximum of 1 second.
?9a]
Fault:
The DBA control panel is defective.
Yes
2)
No heating operation and no hot water. box 41
?9f]
Fault:
The contacts of the gas valve have been broken.
Yes
2)
No heating operation and no hot water. box 40
?9h]
Fault:
The DBA control panel is defective.
Yes
2)
No heating operation and no hot water. box 41
?9l]
Fault:
The contacts of the gas valve have been broken.
Yes
2)
No heating operation and no hot water. box 40
?9l]
Fault:
The DBA control panel is defective.
Yes
2)
No heating operation and no hot water. box 41
box 20 Display codes
Display indication
z
Display
code
Key to display code
Reset
required?
Other symptoms Diagnosis
1) This error code may deactivate again automatically after a specific time (without reset). Heating and hot water are now available once more.
2) In the event of this malfunction, the pump is started up and remains in continuous operation in order to minimise the possibility of the heating system
freezing up.