Buderus 600 - 11S Installation And Servicing Instructions page 51

Servicing
5.3.12 Replacing the safety sensor
Shut the servicing valve.
Drain the 600 - 11S / 19S / 24S / 24C as per the "Installation
and Servicing Instructions".
Loosen the plug-in connection (fig. 68, item 1).
Unscrew the sensor (fig. 68, item 2) and replace with a new
unit.
Plug in cable connection.
Open servicing valves.
NOTE
Fill the 600 - 11S / 19S / 24S / 24C and purge
the system of air.
5.3.13 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. 69).
If the cables are in order, plug them in.
Connect system to mains power supply.
Turn the mains power switch to "I".
5.3.14 Checking the flow sensor
Unplug cable connection from sensor.
Measure resistance of sensor (fig. 70, item 1).
Use a second-reading thermometer to measure the
temperature around the sensor.
Compare readings with values shown in table 8 on
page 53. 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!
Installation and maintenance instructions for wall-mounted condensing gas boiler 600 - 11S/19S/24S/24C • 05/2004
Fig. 68 600 - 11S / 19S / 24S / 24C:
replacing the safety sensor
Fig. 69 600 - 11S / 19S / 24S / 24C:
checking the safety sensor connection lead
1
Fig. 70 600 - 11S / 19S / 24S / 24C:
checking the flow sensor
Boulter Buderus Ltd. • http://www.boulter-buderus.co.uk
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