Servicing
5
46
Installation and servicing instructions condensing gas boiler 800 - 24/29/43/60 and 800 - 24T25/29T25 H/V • edition 02/2006
Subject to modifications resulting from technical improvements !
Buderus • http://buderus-domestic.co.uk
5.3
Checking and replacing parts
5.3.1
Unblock the 800 Series
Each time a fault has been rectified, push the “reset” button
(fig. 53) and keep it pressed for five seconds. A letter “
r
” will
appear on the display. After five seconds, the display returns
to “
0
”. This unblocks the UBA and returns it to standby mode.
5.3.2
Chimney sweep mode
Certain troubleshooting tasks must be carried out with the
800 Serie in heating mode. When doing so, the chimney
sweep switch should be set to “
1
”.
Remember to return the chimney sweep switch to “
0
” once
work is complete.
z
Remove cover of control level 2.
z
Set chimney sweep switch (fig. 54) to “
1
”.
5.3.3
Checking the fuses
z
Disconnect the system from the power supply.
z
Swivel the UBA to one side.
z
Check fuse for throughput or carry out visual
inspection (fig. 55, items 1, 2 and 3).
If defective, fit new fuse (1.25 AT).
z
Connect system to mains power supply.
fig. 53 “Reset” button
display
service
reset
pump
reset
servi
1 2
10
0 1
11
KW
10
1
10
1
I
0
1
NOTE
The system cannot be unblocked by
disconnecting at the master switch.
fig. 54 Chimney sweep switch
1
2
10
0
1
11
KW
10
1
10
1
0
1
1
I
0
NOTE
The system cannot be used for heating water
while it is in chimney sweep mode.
fig. 55 Checking the fuses
1
2
3
4
5
6
7
8
9
10
24VAC
- max 6 VA
0
24VAC
1
2
3
4
5
6
12
11
1
2
3
