Technical data

Installation and servicing instructions for wall-mounted condensing gas boiler Buderus 600 - 11R/19R/24R • 02/2006 59

Subject to modifications resulting from technical improvements! Buderus • http://www.buderus-domestic.co.uk

Servicing 5

5.3.10 Checking the safety sensor connection lead

Check to ensure that all plug-in connections on the

sensor and 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 power switch to “0”.

z Disconnect the system from the power supply.

z Unplug cable connection from flow sensor (fig. 60,

item 1).

z Disconnect 18-pin plug from UBA (fig. 60, item 2).

z Use a continuity tester to check the cable between

the plug-in connection and the 18-pin plug in the

UBA. The test should be carried out on connections

06-18 and 08-18 (fig. 60).

z If the cables are in order, plug them in.

z Connect system to mains power supply.

z Turn the power switch to “I”.

5.3.11 Checking the flow sensor

z Unplug cable connection from sensor.

z Measure resistance of sensor (fig. 61, item 1).

z Use a second-reading thermometer to measure the

temperature around the sensor.

z Compare readings with values shown in table 6. If

there is any mismatch (i.e. > 5%), the sensor is

defective.

z If the sensor is working correctly, plug it in once

more.

Fig. 60 Buderus 600 - 11R / 19R / 24R:

checking the safety sensor connection lead

Fig. 61 Buderus 600 - 11R / 19R / 24R:

checking the flow sensor