Buderus 600 - 11S Installation And Maintenance Instructions Manual page 46

5 Servicing
Open the UBA housing (fig. 55).
Note the position of the cable plugs, disconnect all cable
plugs.
Open the mains connection box by loosening the screw.
Loosen the four screws and remove the strain-relief clamp.
Carefully lift the UBA and remove by pulling forwards (snap
lock) (fig. 56).
Fit new UBA.
Reconnect all plug-in cables to their correct sockets.
Feed the mains lead in through the strain-relief clamp in the
connection box and connect to the terminals as per the
wiring diagram.
Retighten the strain-relief clamp and shut the connection
box.
Shut the mains connection box.
Shut the UBA housing.
Swivel the UBA housing upwards and screw into place.
Fit the casing.
Connect system to mains power supply.
5.3.4 Checking the fan
Set the mains switch to "0".
Disconnect the fan's plug and socket connection.
Connect a multimeter (230 V AC).
Turn the mains power switch to "I".
Take voltage reading at measuring device.
If the voltage reading is 230 V, the power supply is in order.
Set the mains switch to "0".
If the power supply is in order, plug the unit in once more.
Turn the mains power switch to "I".
If the fan now fails to run, it must be replaced.
If the fan runs at only partial load (i.e. effective operation of
the boiler is not possible), troubleshooting should start at
the connection cable to the UBA or UBA.
Buderus • http://www.buderus-domestic.co.uk
46 Installation and maintenance instructions for wall-mounted condensing gas boiler 600 - 11S/19S/24S/24C • 02/2006
Fig. 55 Opening the UBA housing
Fig. 56 Carefully lift the UBA to remove
Fig. 57 Checking the fan
Subject to modifications resulting from technical improvements!