Buderus Logamax GB062-24 KDE H V2 Service Manual page 38

4
Fault finding
EP
The "OK" button was actually pressed for at least 5 seconds (= reset) or short circuit form low voltage cable to the
frame.
Step
1. Is blinking error code on display?
2. Check the low voltage cable (STB, gas
valve cable) for short circuit to the frame.
3. Electronic board (PCB) is defect.
(Gradient Monitoring)
Rapid overshooting of the flow water temperature (Gradient control) (Heating circuit is blocked for 2 min.)
Step
Are the maintanace valves (flow / return)
1.
open ?
2. Check the main (WB6) and plate
heatchanger.
Is there any blockages or damages?
3. Electronic board (PCB) is defect.
38
Remedy
no: --> 3.
B Press the RESET button and start the boiler again.
yes:
EP ? --> 3.
B Switch off the boiler.
B Cut the main voltage supply.
B Replace the low voltage cable.
B Switch on the main voltage supply.
B Switch on the boiler.
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.
Remedy
yes: -->2.
B Open the valves.
no:
Error continuing ? -->2.
no: -->2.
B Remove the blockages or replace it.
yes:
Error continuing ? -->2.
B Switch off the boiler.
B Cut the main voltage supply.
B Remove the pump blockage or replace it.
B Switch on the main voltage supply.
B Switch on the boiler.
B END.
Logamax Plus GB062