Fault / Cause / Remedy; Troubleshooting - Wolf CGU-2-18 Installation And Maintenance Instructions Manual

Any faults will be displayed as fault code by Wolf controllers with eBUS capability. To these faults, cause and remedy may be
allocated using the following table. This table is designed to allow your local heating contractor to trace the fault more easily.
Fault Fault
code
1 TBV excess
temperature
4 No flame established
5 Flame failure during
operation
6 TW excess temperature The flow/return temperature has exceeded the
7 TBA excess
temperature
8 Flue gas damper does
not activate
10 Flow sensor 2 faulty
11 Flame pretence
12 Flow sensor 1 faulty
14 Cylinder sensor faulty
15 Outside temperature
sensor faulty
22 Lack of air
23 Fault differential
pressure switch
25 Gas fan fault
26 Gas fan fault
40 System pressure switch
fault
41 Flow monitoring
45 Fault sensor
Flow rate
46 Fault DHW outlet
temperature
52 Max. cylinder heating
time exceeded
78 Manifold sensor faulty
62

Troubleshooting

Cause
The flow temperature has exceeded the limit for
the TBV shutdown temperature.
Heat exchanger severely contaminated.
No flame established during the burner start.
Flame failure during
flame stabilisation or soft start.
limit for the TW shut-down temperature.
Maximum flue gas temperature exceeded.
Flue gas damper or its feedback faulty.
Sensor 2 for the flow temperature or
the lead is faulty.
A flame is recognised before the
burner starts.
Sensor 1 for the flow temperature or
the lead is faulty.
DHW temperature sensor or lead faulty.
The sensor for the outside temperature or
the lead is faulty.
Differential pressure switch will not switch ON.
Differential pressure switch does not switch OFF.
The gas fan does not reach the set speed.
The gas fan does not stop.
The system pressure switch has responded.
Flow temperature 1 > flow temperature 2 + 12 K ,
temperature change too great.
Lead or sensor faulty or not connected.
Lead or sensor faulty or not connected.
The cylinder heating time takes longer than is set.
The manifold sensor is outside its permitted range. Check manifold sensor, replace.
Remedy
Check the system pressure. Check the heating
circuit pump. Check the HC pump step switch.
Vent the heating system. Press reset button.
Clean the heat exchanger.
Check the gas supply line and open the gas valve,
if necessary.
Check the ignition electrode and ignition cable.
Press the reset button.
Check CO2 Values. Check ionisation electrode and
cable.
Check the system pressure. Vent the system.
Set the pump to stage 2 or 3.
Clean burner, check gas pressures
Check lead.
Replace flue gas damper.
Check bridges in junction box.
Check lead.
Check/replace flow temperature 2.
Check the ionisation.
Press the reset button.
Check lead.
Check/replace flow temperature 1.
Check lead.
Check/replace cylinder sensor.
Check lead.
Check/replace outside temperature sensor
Press the reset button; check the silicone hoses
to the differential pressure switch. Check flue gas
system and gas fan.
Check the differential pressure switch.
Press reset button;
replace the differential pressure switch, if required.
Press the reset button, check the gas fan lead
cable, check the flue gas fan and replace the gas
fan.
Press the reset button, check the gas fan lead
cable, check the flue gas fan and replace the gas
fan.
Check the system pressure switch.
Check the system pressure.
Vent the heating system, check the system
pressure.
Check heating circuit pump.
Check the lead and replace the sensor, if required.
Check the lead and replace the sensor, if required.
Check drawing rate, check DHW cylinder.
(The calculation of the set flow temperature
changes according to the flow sensor).
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