Technical data

Installation and Operation manual ETHOS 36C and ETHOS 54C –1511/05-issue1
Page 24
In addition, there are a number of failures or problems which cannot be shown on the display.
Below a number of these failures or problems are listed:
Symptom Cause of failure
(see table 11):
a Room temperature not reached, appliance does fire 45;53;54
b Noisy ignition 35
c Boiler runs continuously but CH water does not warm up 45
d Room thermostat demands heat, but boiler does not ignite 1;42;52
e Boiler firing continuously, house too warm 2
f Boiler is very noisy in CH operation 29;46;66
g Top of radiators not getting hot enough 55
h Water drawn off but water from the hot tap remains cold 24;56
i Domestic Hot water much too hot 51;57
j Water is drawn off, but the water from the hot tap does not reach 60°C 51;58
k Boiler very noisy during DHW operation 23;59
l Fault after replacement of burner control unit 60
6.1 Cause of failure
Failures can be caused the following:
1. Room thermostat is not connected properly.
2. Room thermostat does not switch off, short circuit in cable.
3. Sensor has caused a short circuit in the cable or internally.
4. Pump does not rotate; is stuck.
5. Water pressure in central heating installation is too low.
6. Water pressure in central heating installation is too high.
7. Fan is not connected (plug is not connected).
8. Fan is dirty.
9. Fan is defective.
10. Gas tap is not turned on.
11. Gas pressure is too low.
12. Gas pipe diameter too small.
13. Code key not installed; code key not connected properly to burner control unit; wrong type of code key.
14. Fuse defective.
15. This code is shown after programming with a PC.
16. Gas valve setting at lowest speed is wrong.
17. Gas valve is not or not properly connected electrically.
18. Ignition cable interrupted or not connected properly.
19. Transformer defective.
20. Gas valve connector not fitted properly or moisture inclusions.
21. Pump connector not fitted properly.
22. Siphon clogged.
23. Air in system; open and close manual bleeder after bleeding.
24. Three-way valve is dirty.
25. Resistance in the discharge system too high or discharge system dirty.
26. Discharge system is leaking toward supply system; flue recirculation only at concentric connection.
27. Supply system lets in water.
28. Flow adjusting cock is dirty; if applicable, check bypass, filter dirty.
29. Heat exchanger interior is dirty (insufficient circulation)
30. High limit thermostat defective (insufficient circulation)
31. Max. heat input too high.
34. Burner control unit defective.
Table 11 Cause of failure
Table 10 Other types of failures