27
SECTION 3 - SERVICING
Note.
Fit the earth strap provided with the PCB to your
wrist and a suitable earth on the boiler chassis.
1.
Refer to Frame 3.8.
2.
Remove the main PCB, refer to Frame 3.18.
3.
Unclip the PCB and lift to clear the mounting posts.
4.
Fit the new PCB ensuring the 3 potentiometer
spindles line up with the control knobs which must
be in a vertical position.
5.
Reassemble in reverse order.
6.
Check operation of the boiler.
3.19 USER CONTROL PCB REPLACEMENT
3
Potentiometer spindle
Control Knobs (to be in vertical position)
PCB
4
1.
Refer to Frame 3.8.
2.
Swing the boiler lower front panel into the service
position. Refer to Frame 3.2.
3.
Remove the 4 fixing screws.
4.
Disconnect the 4 push on connectors.
5.
Remove programmer.
6.
Re-fit 4 push on connectors to new programmer.
7.
Fit programmer and retain with 4 screws previously
removed.
8.
Replace the lower front panel.
9.
Check operation of the boiler.
3.20 REPLACING THE MECHANICAL TIMER
19
20
21
22
23
24
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
00
I
preheat
preheat
min
min
max
mode
reset
off
status
burner
max
e
3
4
Summary of Contents for GB24
Page 43: ...43 NOTES ...
