Servicing
5
52
Installation and servicing instructions condensing gas boiler 800 - 24/29/43/60 and 800 - 24T25/29T25 H/V • edition 02/2006
Subject to modifications resulting from technical improvements !
Buderus • http://buderus-domestic.co.uk
5.3.11 Replacing the mains-water sensor
z
Unplug cable connection from mains-water sensor.
z
Pull mains-water sensor out and push new unit in.
z
Plug in cable connection.
5.3.12 Checking the cables to the flow, return and safety
sensors, and to the burner thermostat
Check to ensure that all plug-in connections to the
sensors/burner thermostat
and in the UBA
are in order. Note
that an incorrectly-inserted plug can lead to the generation of
error messages. Start up the boiler by pressing the “reset”
button.
z
Set the mains switch to “
0
”.
z
Disconnect the system from the power supply.
z
Unplug the cable connection from the sensor/burner
thermostat.
z
Check the cable between the plug-in connection and the
24-pin plug in the UBA with a continuity tester.
z
If the cables are in order, plug them in.
z
Connect system to mains power supply.
z
Set the mains switch to “
I
”.
fig. 70 Replacing the mains-water sensor
fig. 71 Checking the cable to the flow/return sensors
Rear side
of UBA
Flow sensor
Retur n sensor
Red wire slee ve
fig. 72 Checking the cable to the safety sensor
