Buderus 600-19R Installation And Servicing Instructions page 44

5 Servicing
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.
Set the mains switch to "0".
Disconnect the system from the power supply.
Unplug cable connection from flow sensor.
Disconnect 18-pin plug from UBA.
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. 50).
If the cables are in order, plug them in.
Connect system to mains power supply.
Turn the mains power switch to "I".
5.3.11 Checking the flow sensor
Unplug cable connection from sensor.
Measure resistance of sensor (fig. 51, item 1).
Use a second-reading thermometer to measure the
temperature around the sensor.
Compare readings with values shown in table 8. If there is
any mismatch (i.e. > 5%), the sensor is defective.
If the sensor is working correctly, plug it in once more.
Subject to modifications resulting from technical improvements!
44 Installation and maintenance instructions for wall-mounted condensing gas boiler Buderus 600 - 11R/19R/24R • 05/2004
Fig. 50 Buderus 600 - 11R / 19R / 24R:
checking the safety sensor connection lead
1
Fig. 51 Buderus 600 - 11R / 19R / 24R:
checking the flow sensor
Temp. Resistance
[°C] [Ω]
0 29,490
5 23,462
10 18,787
15 15,136
20 12,268
25 10,000
30 8,197
35 6,754
40 5,594
45 4,656
50 3,893
Table 8 Resistance values for hot water / boiler sensor
(approximate values)
Boulter Buderus Ltd. • http://www.boulter-buderus.co.uk
Temp. Resistance
[°C] [Ω]
55 3,271.0
60 2,760.0
65 2,339.0
70 1,990.0
75 1,700.0
80 1,458.0
85 1,255.0
90 1,084.0
95 1,939.6
100 1,817.2