3064816_201804
91
40. Troubleshooting
Fault
code
Fault
Possible causes
Remedy
12
Boiler sensor faulty
Excess temperature in the flow
Boiler sensor > 100 °C
Boiler sensor or sensor lead has short
circuit or lead break
Pump
Pump:
- Check if pump is running. If not, check
cables and plugs. If electrical connection
OK but no function, replace the pump.
Excess flow temperature:
- Increase the minimum pump speed.
Boiler sensor:
- Check leads and plug-in connections.
- If OK but no function, replace the boiler
sensor.
Press reset button.
13
Flue gas sensor faulty
Flue gas sensor or sensor lead has
short circuit or lead break
Flue gas temperature sensor:
- Check leads and plug-in connections.
- If electrical connection OK but no function:
Replace the sensor.
Press reset button.
14
DHW sensor faulty
DHW sensor (cylinder sensor) or sensor
lead has short circuit or lead break
DHW sensor > 99 °C
DHW temperature sensor:
- Check leads and plug-in connections.
- If OK, replace sensor.
Press reset button.
15
Outside sensor faulty
Outside sensor or sensor lead has short
circuit or lead break
eBUS outside sensor
Wireless outside sensor
eBUS outside sensor
- See instructions for eBUS outside sensor.
Wireless outside sensor
- See instructions for wireless outside sen-
sor.
Press reset button.
16
Return sensor faulty
Return sensor or sensor lead has short
circuit or lead break
Return sensor > 100 °C
Return sensor:
- Check leads and plug-in connections.
- If OK but no function, replace the return
sensor.
Press reset button.
20
GCV relay test
Valve test failed
Gas valve faulty
Replace gas valve.
Press reset button.
24
Fan speed <
Set fan speed is not achieved
Control unit casing not engaged
Fan faulty
F2 fuse defective on HCM-2
Fan:
- Check cables, plug-in connections, power
supply and switching.
- If OK but no function: Replace the fan.
Control unit casing not engaged:
- Check that top and bottom sections of
control unit casing are engaged.
Check F2 fuse on HCM-2 control PCB
Press reset button.
26
Fan speed >
The fan does not stop
Fan:
- Check cables, plug-in connections, power
supply and switching.
- If the fault occurs repeatedly, replace fan.
Press reset button.
27
DHW outlet sensor faulty
Stratification sensor
faulty
DHW outlet sensor/stratification sensor
or sensor lead has short circuit or lead
break
DHW outlet sensor/stratification sensor
- Check cables and plug-in connections.
- If OK but no function, replace the sensor.
30
CRC burner control unit
The EEPROM record is invalid.
EEPROM record invalid:
- Switch power supply OFF/ON.
- If fault persists, call out a contractor.