Buderus 500 - 28/C Servicing Manual page 35

box 37
:6c]
Is the ionisation current displayed?
step 1
Disconnect the plug-and-socket connection, see box 144.
step 2
Is the ionisation current still displayed?
step 3
Check the plug-and-socket connection between the ionisation electrode and cable loom, see box 144.
step 4
Is the plug-and-socket connection in full working order?
step 5
Correctly insert the plug into its socket.
step 6
Check the cable of the ionisation electrode, see box 151.
step 7
Is the wiring in order?
step 8
Replace the cable loom (or the affected part thereof).
step 9
Check the ionisation electrode, see box 149 or box 155.
step 10
Is the ionisation electrode working correctly?
step 11
Replace the ionisation electrode, see box 155.
step 12
Switch the boiler off and then on again at the operating switch.
step 13
The following components should be checked for soiling, damage and/or correct installation:
step 14
- syphon, see box 256
- flue-gas pipework.
Check the pressure control valve, see box 85.
step 15
Is the pressure control valve working correctly?
step 16
Replace or clean the pressure control valve, see box 85.
step 17
box 38
[6c]
Connect a digital pressure gauge, see box 233 and 234. Open the gas cock and place the boiler into full-load
step 1
operation, see box 59 or box 13. Deactivate the heat requirement as per flue-gas test (box 13), and check to
see if the burner remains under pressure after the "heat requirement" symbol on the DBA control panel goes
out.
Is the burner still under pressure?
step 2
Check the ionisation electrode, see box 37.
step 3
Close the gas cock, see box 46. Remove the digital pressure gauge and close the burner-pressure
step 4
connection nipple. Open the gas cock, see box 59, and run the boiler at full load once more, see box 59 or
box 13. Deactivate heat requirement, see box 13, and check to see if the gas valve is still powered after the
"heat requirement" indicator goes out, see box 165, item 1 and 2.
Is the gas valve still powered?
step 5
Replace the gas valve, see box 174.
step 6
We reserve the right to make technical modifications
Servicing manual Gas condensing boiler Buderus 500-24/S, 500-24/C and 500-28/C • Issued 02/2006
The system has detected an ionisation current before burner startup.
Locking boiler-fault code
An ionisation current has been measured as soon as the burner shuts down.
Locking boiler-fault code
Diagnosis
Yes:
No:
Yes:
No:
Yes:
No:
Yes:
No:
Yes:
No:
Yes:
No:
Yes:
No:
Yes:
No:
Buderus Ltd. • http://www.buderus-domestic.co.uk
6
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step 2
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step 1
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step 12
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box 41
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step 7
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step 6
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step 11
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step 10
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step 9
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step 13
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box 42
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step 14
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step 12
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box 42
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box 41
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step 17
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box 42
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step 4
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step 3
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box 41
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step 6
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