Bosch Condens 2000 W - Page 10

10 | Failures / Errors
A6 and operating LED is flashing.
Combustion chamber NTC failure (behind burner) : when NTC not detected or open circuit
Control Step Action
1. Check if combustion chamber NTC dam-
aged or not and the position.
B Switch off the appliance.
B Pull the NTC cables out.
B Measure NTC resistance.
Are the values correct ? (see NTC val-
ues)
yes: B Check the cable connection.
A6 failure still exist ? -->2.
no: B Change the NTC.
B Connect the cable.
B Switch on the appliance.
A6 failure still exist ? -->2.
2. Check if cable damaged or not.
B Switch off the appliance.
B In case of NTC is cahnged :
- Pull the NTC cables out.
- Measure NTC resistance.
- Reconnect the NTC cable.
B Pull out the 20 poled connector on
control unit.
B Measure the NTC resistance directly
on 20 poled connector. Are the meas-
ured values on NTC and cocnector dif-
ferent ?
yes: B Change the cable harness.
B Switch on the appliance.
A6 failure still exist ? -->3.
no: -->3.
3. Electronic card is defect. B Switch off the appliance.
B Cut mains supply.
B Change the electronic card.
B Connect to main supply.
B Switch on the appliance.