Buderus 500 - 24/C, Servicing Manual

Page: 36 / 80

Diagnosis 6
We reserve the right to make technical modifications Buderus Ltd. • http://www.buderus-domestic.co.uk
36 Servicing manual Gas condensing boiler Buderus 500-24/S, 500-24/C and 500-28/C • Issued 02/2006
box 39
The power supply was shut off during operation.
Locking boiler-fault code
step 1
Reset the boiler with button "
B
", or by turning the operating switch to "OFF" and then "ON" again.
step 2
Is the error code still displayed? Yes:
→
step
3
No:
→
box
42
step 3
Interpret the fault code now displayed in box 20 and deal with the malfunction.
box 40
The contacts of the gas valve have been broken.
Locking boiler-fault code
step 1
Check the plug-and-socket connection of the gas valve, see box 161.
step 2
Is the plug-and-socket connection in full working order? Yes:
→
step
4
No:
→
step
3
step 3
Reconnect the plug-and-socket connection, see box 161.
→
box
42
step 4
Measure the cable between the gas valve and DBA control panel, see box 164.
step 5
Is the cable correctly connected and free of damage? Yes:
→
step
7
No:
→
step
6
step 6
Replace the cable loom (or the affected part thereof).
→
box
42
step 7
Measure the resistance of the gas valve coils, see box 171.
step 8
Is the resistance correct? Yes:
→
box
41
No:
→
step
9
step 9
Replace the gas valve, see box 174.
→
box
42
box 41
Bad electrical contacts, circuit board or EEPROM (KIM) of DBA control panel defective.
step 1
Check the contacts on the circuit board of the DBA control panel by pushing fully home the plug-and-socket
connections on the board; check and deal with any other contact problems with plug-and-socket connections.
step 2
Switch the boiler off and then on again at the operating switch.
step 3
Is same fault warning message still displayed? Yes:
→
step
4
No:
→
step
8
step 4
Check the plug-and-socket connection on the EEPROM (KIM), see box 284.
step 5
Has the DBA control panel been replaced? Yes:
→
step
7
No:
→
step
6
step 6
Replace the DBA control panel, see box 281.
→
step
2
step 7
Contact Buderus (see on the back of this manual).
step 8
Has a new fault occurred? Yes:
→
step
9
No:
→
box
42
step 9
Interpret the fault code now displayed in box 20 and deal with the malfunction.
[7c]
[9f]
[9l]