Troubleshooting
3
Subject to modifications resulting from technical improvements!
Buderus Ltd. • http://www.buderus-domestic.co.uk
66
Servicing manual for wall-mounted condensing gas boiler 600 Series 11S/19S/24S/24C • Issued 02/2006
3.1.34 Checking the ERC/RC connections to the UBA
z
Disconnect the system from the power supply.
z
Loosen crosshead screw on UBA housing.
z
Swivel the UBA housing downwards (fig. 88).
z
Push in UBA housing on left-hand side and open to the
right (fig. 89).
z
Check to ensure that ERC or RC are correctly connected
to 3 and 4.
z
Terminals 1 and 2 should not be wired in any way.
The unit is supplied with a dummy connector between
terminals 1 and 2 (fig. 90). The DC voltage at terminals 3
and 4 should be approx. 11.5 V. If this is not so, the UBA
or the cable harness is defective.
z
Shut the UBA housing once more.
z
Swivel the UBA housing upwards and screw into place.
z
Connect system to mains power supply.
z
Set the mains switch to “
I
” and press the “reset” button.
3.1.35 Replacing the terminal strip
z
Note order of cable terminals. Loosen all cables.
z
Connect the cables, in the right order, to the new terminal
strip.
Fig. 88 Swivel UBA housing downwards
Fig. 89 Opening the UBA housing
