Buderus 500 - 24/C, Servicing Manual

Page: 29 / 80

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 29
step 16
Replace the by-pass valve.
→
box
42
box 28
The flue-gas STL (fume-monitoring device) has detected a temperature higher than
105°C. The flue-gas STL is open.
Locking boiler-fault code
step 1
Check to ensure that the restrictor baffle has been installed as per box 261, item 1.
step 2
Has the restrictor baffle been fitted? Yes:
→
step
4
No:
→
step
3
step 3
Fit the restrictor baffle, see box 261, item 1.
→
box
42
step 4
Check the entire system of flue gas pipe for restrictions.
step 5
Is the entire system of flue gas pipe in full working order? Yes:
→
step
7
No:
→
step
6
step 6
Deal with restriction.
→
box
42
step 7
Check the flue-gas STL, see box 120.
step 8
Is the flue-gas STL working correctly? Yes:
→
step
10
No:
→
step
9
step 9
Replace the flue-gas STL, see box 129.
step 10
Check the wiring of the flue-gas STL, see box 126.
step 11
Is the wiring of the flue-gas STL in full working order? Yes:
→
box
41
No:
→
step
12
step 12
Replace the cable loom (or the affected part thereof).
→
box
42
box 29
The tacho signal from the fan has failed during the operating phase.
Blocking boiler-fault code
The tacho signal from the fan is not present during the pre-operative or operating
phase.
Locking boiler-fault code
step 1
Check to ensure that both plug-and-socket connections of the fan are correctly fitted, see box 246, item 1.
step 2
Are the plug-and-socket connections fitted correctly? Yes:
→
step
4
No:
→
step
3
step 3
Reconnect the plug-and-socket connection of the fan.
→
box
42
step 4
Check fan, 230V AC supply, see box 66 or box 287.
step 5
Does activation take place correctly? Yes:
→
step
9
No:
→
step
6
step 6
Check the power supply cable of the fan (230V AC), see box 69.
step 7
Is the power supply cable of the fan in full working order? Yes:
→
box
41
No:
→
step
8
step 8
Replace the cable loom (or the affected part thereof).
→
box
42
step 9
Check tacho cable of fan, see box 73.
step 10
Is the tacho cable in full working order? Yes:
→
step
12
No:
→
step
11
step 11
Replace the cable loom (or the affected part thereof).
→
box
42
step 12
Check to ensure that the mains voltage at the earthed (grounded) plug is between 195V and 253V AC.
box 27
[1c]
C [3a]
[3l]