Installation
1
Installation and maintenance instructions for wall-mounted condensing gas boiler 600 - 11S/19S/24S/24C • 02/2006
19
Subject to modifications resulting from technical improvements!
Buderus • http://www.buderus-domestic.co.uk
1.10.1 External controls
The wall-mounted condensing gas boiler can be fitted with the
following control devices:
– ON/OFF temperature controller, volt free;
– A room-temperature control device at 230V connected to
the connection plate (fig. 20, item 1).
– A modulating room-temperature control device at 24 Volt
connected to the connection plate (fig. 22, item 1) such as
the 250 RF ModuLink and the
i
RT controllers.
1.10.2 External 230V controls
z
Loosen crosshead screw (fig. 18, item 1) on burner-control
unit (UBA).
z
Swivel burner-control unit downwards.
z
Open the back of the burner-control unit to the right
(fig. 19).
z
Connect the black pre-wired lead to a permanent live
supply (from the same fused isolator as all other controls
on the heating system), L N E.
z
Feed the 230V switch live and neutral (from external
controls) through the cable lead.
z
Identify the 230V terminal block by the shaded area and
230V label.
z
Connect the switch live to terminal "1" and a neutral to
terminal "2" (fig. 20, item 1).
z
Replace covers.
Fig. 18 Swivel the housing of the burner-control unit
downwards
1
Fig. 19 Open back of the burner-control unit
Fig. 20 Connection box in burner-control unit -
230V connection
1
2
NOTE
Terminal 3 (fig. 20, item 2) is not used.