Technical data

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

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

Servicing5

5.3.7 Checking the miniature fuses

z Disconnect the system from the power supply.

z Loosen the two fixing screws and carefully turn the

UBA around.

z Check miniature fuses (fig. 57) for correct func-

tioning, or carry out visual inspection. If defective, fit

new fuse (1.25 AT).

z Turn the UBA around and place back onto the

bracket.

z Tighten the two screws.

z Connect system to mains power supply.

5.3.8 Checking the safety sensor

z Unplug cable connection from sensor.

z Measure resistance of sensor (fig. 58, item 1).

z Use a second-reading thermometer to measure the

temperature around the sensor.

z Compare readings with values shown in table 6 on

page 60. If there is any mismatch (i.e. > 5%), the

sensor is defective.

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

more.

5.3.9 Replacing the safety sensor

z Shut the servicing valve.

z Drain the Buderus 600 - 11R / 19R / 24R as per the

"Installation and Servicing Instructions".

z Loosen the plug-in connection (fig. 59, item 1).

z Unscrew the sensor (fig. 59, item 2) and replace with

a new unit.

z Plug in cable connection.

z Open servicing valves.

Fig. 57 Checking the miniature fuse

Fuse Function

1 Glow ingitor

2 UBA, sensors, thermostat valve

3UBA

Fig. 58 Buderus 600 - 11R / 19R / 24R:

checking the safety sensor

Fig. 59 Buderus 600 - 11R / 19R / 24R:

replacing the safety sensor

NOTE

Fill the Buderus 600 - 11R / 19R / 24R and

purge the system of air.