HDG Compact 25, Operation Manual

Page: 167 / 188

8 Troubleshooting – Procedure
167
8 Troubleshooting
If a fault occurs in the heating system, all of the operating mode sym-
bols flash and the fault is shown in the display. Faults can be fixed as
follows.
8.1 Procedure
1. Look for the displayed fault, its cause and remedy in Table 8.2
“Possible faults”.
2. Fix the fault, or have it fixed.
3. Acknowledge the fault with the Enter button.
4. For faults which affect safety, switch the main switch off and back
on again after waiting a few seconds.
✓
The symbol for the current operating mode lights up.
✓
The fault message is no longer shown in the display.
✓
The fault is fixed.
8.2 Possible faults
Enter
No. Fault Cause Remedy
No text display shown • Main circuit breaker tripped
•
Mains supply is not connec-
ted
• Heating Emergency Stop
switched off
• Main switch not switched on
• Check fuses, power supply
and main switch
No text display
Power supply OK • Microfuse F3 (on I/O circuit
board) is faulty
• Data cable not plugged in
properly
•
Display is faulty
• Check microfuse and replace
if necessary
• Check data cable
• Replace display
F001 Safety thermos-
tat
• Excessive boiler temperature
• Wiring is faulty
•
Fuse F2 (on I/O circuit board)
faulty
• Allow boiler to cool to under
90 °C, unscrew protective cap
from STL and press button
• Have STL line checked by a
qualified electrician
•
Replace fuse F2
Table 8/1 - Faults