Buderus Logamax GB062-24 KDE H V2 Service Manual page 29

4C
- Heat exchanger temperature limiter or flue gas temperature limiter has tripped.
- The differential pressure switch does open when the fan runs (after ignition) (only high modulation version).
Step
9. B Switch off the boiler.
B Check the flue gas 6Apipe/system
for blockage (In case of blockage,
due to high pressure the contacs of
diff. presure switch is opening--> 4C)
Is there a blockage in flue gas pipe ?
10 Electronic board (PCB) is defect.
Logamax PLus GB062
Step
no: 4C ? --> 10.
B Correct the flue gas installation (remove the blockage).
yes:
B Switch on the boiler.
--> 10.
B Switch off the boiler.
B Cut the main voltage supply.
B Change the electronic board (PCB).
B Switch on the main voltage supply.
B Switch on the boiler.
B END
4
Fault finding
29