Buderus 500 - 24/C, Servicing Manual

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Diagnosis 6
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Servicing manual Gas condensing boiler Buderus 500-24/S, 500-24/C and 500-28/C • Issued 02/2006 31
box 32
The flow NTC sensor has detected a temperature of over 105 °C.
Locking boiler-fault code
step 1
Check the flow rate in the heating circuit.
step 2
Are all servicing valves and thermostat valves closed? Yes:
→
step
4
No:
→
step
3
step 3
Check all servicing valves and thermostat valves for correct functioning
step 4
Open all servicing valves and thermostat valves.
step 5
Has the malfunction been repaired? Yes:
→
box
42
No:
→
box
41
box 33
The sensor test has failed.
Locking boiler-fault code
step 1
Check the flow NTC sensor and safety sensor and their wiring for short circuits, see box 104 to 115 and
box 287.
step 2
Are the flow NTC sensor and safety sensor, along with their wiring, in correct working order? Yes:
→
box
41
No:
→
step
3
step 3
Replace the flow NTC sensor, safety sensor, cable loom or corresponding component of the cable loom,
see box 116.
→
box
42
box 34
The contacts of the flow NTC 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.
Locking boiler-fault code
step 1
Are the servicing valves open? Yes:
→
step
3
No:
→
step
2
step 2
Open the servicing valves, see box 53.
step 3
Is the pressure of the heating system water at least 1 bar? Yes:
→
step
5
No:
→
step
4
step 4
Fill and vent the heating system, see box 52.
step 5
Are enough thermostatic valves open on the radiators, convectors, etc? Yes:
→
step
7
No:
→
step
6
step 6
Open more thermostatic valves on the radiators, convectors, etc.
→
box
42
step 7
Check the flow NTC sensor and safety sensor, see box 104.
step 8
Are the flow NTC sensor and safety sensor functioning correctly? Yes:
→
step
10
No:
→
step
9
step 9
Replace the flow NTC sensor or safety sensor, see box 116.
step 10
Check the cables of the flow NTC sensor and safety sensor, see box 112.
step 11
Are the cables in order? Yes:
→
step
13
No:
→
step
12
step 12
Replace the cable loom (or the affected part thereof).
→
box
42
step 13
Check the pump, see box 89 to 100.
step 14
Is the pump working correctly? Yes:
→
box
41
No:
→
step
15
[4a]
[4e]
[4l]