Potterton Combi 80, Installation & Service Instructions Manual

Page: 30 / 47

Replacement of Parts - Page 30
Fig 19
5.12 Central Heating and Boiler Switches
1. Remove the white front case and base panel.
See 4.1 & 4.2 in ‘Routine Maintenance’.
Lower the facia panel, (1 screw).
2. Make note of the wire routing and switch orientation and
disconnect the molex plug from the electronic control
board.
3. Using a small screwdriver press the retaining lugs on the
switch body sides inwards and remove the switch from
the control panel. Withdraw the switch and leads and
feed the molex plug through the cut out in the panel
4. Fit new switch assembly and re-assemble in reverse
order. Ensure that the switch is the correct way round in
the panel i.e. when the Stand-by/On switch is On, the
red indicator line on the switch can be seen.
5. Re-fit the molex plug to the correct plug position on the
electronic control board.
5.13 Control Boards
The electronic control assembly is in three parts:
•
The User Display Board.
•
The Control Board.
•
The Full Sequence Control Board.
1. Remove the white front case and base panel.
See 4.1 & 4.2 in ‘Routine Maintenance’.
(i) USER DISPLAY BOARD
1. Undo the fixing screw retaining the facia panel and
swing the panel downwards.
2. Remove the plug connector/s from the rear of the board
and undo the four securing screws.
3. Replace board and re-assemble in reverse order.
(ii) MODULATION CONTROL BOARD
Note:
The board has a replaceable fuse rated at 2A.
1. Undo the fixing screw retaining the facia panel and
swing the panel downwards.
2. Remove the plug connectors on the larger control board
and undo the four securing screws.
3. Replace the board and re-assemble in reverse order.
4. Reset the C.H. range rate - see Section 3.3.(11).
(iii) FULL SEQUENCE CONTROL BOARD
1. Undo the fixing screw retaining the control panel
assembly (top right hand side of control box) and swing
the control assembly downwards.
2. Remove the cover over the full sequence control (two
screws).
3. Slide the electrode and flame sensors wire connections
out of their respective slots on the board. Disconnect all
plug connections and carefully remove the earth tab.
4. At each of the four standoff pillars, push the small barb
inwards and lift the board free.
5. Replace the board and re-assemble in reverse order.