Buderus 500 - 24/C, Servicing Manual

Page: 30 / 80

Diagnosis 6
We reserve the right to make technical modifications Buderus Ltd. • http://www.buderus-domestic.co.uk
30 Servicing manual Gas condensing boiler Buderus 500-24/S, 500-24/C and 500-28/C • Issued 02/2006
step 13
Is the mains voltage sufficient? Yes:
→
step
15
No:
→
step
14
step 14
The cause of the fault lies in the electrical system.
→
box
42
step 15
Replace fan, see box 76.
step 16
Has the malfunction been repaired? Yes:
→
box
42
No:
→
box
41
box 30
No current of air after a certain time.
Locking boiler-fault code
step 1
Attempt to rectify the fault by temporarily replacing the fan, see box 76.
step 2
Has the malfunction been repaired? Yes:
→
box
42
No:
→
box
41
box 31
The fan runs too slowly or too fast.
Locking boiler-fault code
step 1
Check the plug-and-socket connection of the fan tacho cable.
This is the narrow plug, see box 78, item 2.
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 78, item 2.
→
box
42
step 4
Check tacho cable of fan, see box 73.
step 5
Is the tacho cable in full working order? Yes:
→
step
7
No:
→
step
6
step 6
Replace the tacho cable.
→
box
42
step 7
Check to ensure that the mains voltage at the earthed (grounded) plug is between 195V and 253V AC.
step 8
Is the mains voltage sufficient? Yes:
→
step
10
No:
→
step
9
step 9
The cause of the fault lies in the electrical system.
→
box
42
step 10
Check to see if there is a restriction in the fan, burner, heat exchanger or flue-gas system.
step 11
Is there a restriction? Yes:
→
step
12
No:
→
step
13
step 12
Deal with restriction.
→
box
42
step 13
Check to see if there is a second fan in the flue gas pipe or air inlet system.
step 14
Is a second fan fitted? Yes:
→
step
15
No:
→
step
16
step 15
Take second fan out of service.
→
box
42
step 16
Check to see if the fan impeller has come loose at the motor spindle, see box 76.
step 17
Has the fan come loose? Yes:
→
step
18
No:
→
step
19
step 18
Replace fan, see box 76.
step 19
Has the malfunction been repaired? Yes:
→
box
42
No:
→
box
41
box 29
[3l]
[3y]