Buderus 500 - 28/C Servicing Manual page 48

7 Actions
box 105
Pull out the plug of the safety sensor.
box 106
Set multimeter to "measure resistance".
Measure the resistance of the safety sensor.
We reserve the right to make technical modifications
48 Servicing manual Gas condensing boiler Buderus 500-24/S, 500-24/C and 500-28/C • Issued 02/2006
box 107
Pull out the plug of the flow NTC sensor.
box 108
Set multimeter to "measure resistance".
Measure the resistance of the flow NTC sensor.
box 109
Measure the electrical resistance of the flow NTC sensor
and safety sensor.
Measure the electrical resistance of the flow NTC sensor
and check the earth (ground) connection of the safety
sensor. This must be infinitely high.
The measured resistance of the flow NTC sensor is
virtually identical to that of the safety sensor.
Buderus Ltd. • http://www.buderus-domestic.co.uk