Technical information

Combi 70 & Combi 90 Oil Boilers
32
Connection of external remote timeswitch
4.7
Optional plug-in 24 hr mechanical timer
4.8
Connect the power supply
4.6
1 Remove the two screws securing the boiler
terminal block cover (see Fig. 17 or 19) and lift off
the cover. Remove the two screws securing the
cable clamp and open the clamp.
2 Pass the power supply cable through the hole
(using the grommet supplied) in the rear panel and
connect it to the terminal block as follows:-
Brown to Mains Live (L)
Blue to Mains Neutral (N)
Green/Yellow to Mains Earth (E)
3 Connect a room thermostat and/or frost thermostat
as follows:-
Pass the thermostat leads through the grommet
(following the power supply cable route) and
connect to the terminal block as shown in the
wiring diagram on page 47.
Note: If a room thermostat is fitted, remove the
link between terminals 7 and 12 and connect the
thermostat in its place. See section 10.3.
4 Connect an external remote timeswitch (if
required). See section 4.7.
See section 10.3 (10.4 for Grant remote timer)
Important: Any remote timer must be of a single
channel 240V type with voltage free output contacts.
Important: Ensure electrical supply to boiler has
been isolated before fitting the timer.
1 Remove the two screws securing the terminal block
cover (see Fig. 17 or 19) and lift off the cover.
2 Pass a 4-core cable (or 4-core and earth if the timer
to be used has an earth connection) through the
grommet in the rear panel. Connect the two switch
wires from the timer to terminals 13 and 14.
Connect the live, neutral (and earth if required)
from the timer to terminals 1, 2 & 4 respectively on
the boiler terminal block.
See section 10.3 for a typical wiring diagram.
3 Remove the link from terminals 13 and 14 on the
boiler terminal block.
4 Secure the cable in the cable clamp, replace the
wiring cover in position over the terminal block,
taking care not to trap any wires, and secure in
position with the two screws previously removed.
5 Ensure that all external wiring is adequately supported.
6 Do not switch on the electricity supply at this stage.
4 - BOILER INSTALLATION
Important: Ensure electrical supply to boiler has
been isolated before fitting the timer.
1 The Mechanical Timer Kit (Ref. MTKIT) contains
the following items:
One Diehl Type 880 24-hour single channel
mechanical timeswitch
Two plastic fixing clamps
One wiring harness
2 The wiring harness must be connected to the Diehl
Type 880 Mechanical Timer as follows:
Blue wire: To Terminal 1 of timer
Red wire: To Terminal 2 of timer
Brown wire: To Terminal 3 of timer
Brown wire: To Terminal 5 of timer
3 Remove the front top casing panel.
4 Remove the three screws holding the back of the
control panel in place and move it back enough to
allow access to the rear of the timer aperture.
5 From underneath the control panel, remove the
screw securing the bracket behind the timer
aperture. Withdraw and discard the bracket.
6 Remove the blanking piece from the timer aperture,
in the control panel fascia, by firmly pressing on the
Grant logo (in the centre of the black square) until it
is detached from the rear of the fascia. Remove the
blanking piece from the panel and discard.
7 Remove the two screws securing the terminal block
cover (see Fig. 17 or 19) and lift off the cover.
Remove the link from terminals 13 and 14.
8 Fit the 6-way plug on the timer wiring harness,
firmly into the 6-way socket, to connect the timer
to the boiler.
9 Carefully fit the timer into the aperture, and (from the
rear of the control panel) fit the two fixing clamps,
one into the slot on each side of the timer housing,
with the two ‘legs’ towards the front of the timer.
10 With the front of the timer held against the fascia,
push both clamps towards the front of the timer as
far as possible to firmly secure timer in position.
11 Replace the wiring cover in position over the
terminal block, taking care not to trap any wires,
and secure in position with the two screws
previously removed.
12 Replace back of control panel and top casing panel.
Reconnect electricity supply and check operation
of timer. Refer to the User Instructions provided
for operating and setting the timer.