Technical information

29. Fault Finding
The following fault codes (blocking and interlocking) are saved. The last blocking code is
displayed in view mode A. (See Section 27 and table 15).
29.1 Blocking actions
Internal number Description Display code
49, 58 Supply sensor open 1
65, 74 Supply sensor short-circuited 1.
43 Return sensor open 2
59 Return sensor short-circuited 2.
45 External sensor open 4
61 External sensor short-circuited 4.
50 Hot water supply sensor open 6
66 Hot water supply sensor short-circuited 6.
30 Flame detected with a closed gas valve F
40 Flame sensor short-circuited F.
38 Phase and zero reversed U
36 Supply sensor > 100 °C q
25, 26, 27, 28 Reference AD fault E
31, 34, 35 Sample fault E
39 50 Hz fault E
0 E2PROM reading error E
29 Exhaust gas sensor > 80 °C A
41 Watchdog communication error E
32 Water pressure error P
29.2 Interlocks
The last interlock code is displayed in view mode 9 (See Section 27 and table 15).
Internal number Description Display code
1 Ignition fault F
2 Supply sensor fault 1
24 Too many flame faults 2
21 Flame out 2
3 Unknown fault 3
4 Watchdog fault 3
10 E2PROM fault 3
12 Faulty E2PROM Identification 3
19 Stack fault 3
9 Flame out 3
8 Fan fault 5
5 Gas valve relay fault 7
6 Safety relay fault E
7 Ignition relay fault E
11 Supply sensor > 105 °C E
20 Flame not out in time E
14 Exhaust gas sensor > 95 °C A
EC 25 Compact Installation/User Manual page
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