0020244998_04 ecoTEC plus Installation and maintenance instructions
59
Message
Possible cause
Measure
F.68
Fault: Flame signal un-
stable
Flame monitor reports an un-
stable flame signal
▶
Check: Air ratio, gas flow pressure, condensate route (block-
age), gas injector, ionisation flow (cable, electrode), flue gas
recirculation.
F.70
Fault: Invalid Device Spe-
cific Number
Incorrect/missing Device
Specific Number or
incorrect/missing coding resistor
▶
If the display and PCB have been replaced, change the Device
Specific Number under
D.93
.
F.71
Fault: Flow sensor
Flow temperature sensor re-
turns implausible values
▶
Check: Flow temperature sensor (correct thermal connection).
F.72
Fault: Flow/return sensor
Temperature difference
between flow and return
temperature sensor is too great
▶
Check: Flow temperature sensor/return temperature sensor
(function, correct thermal connection).
F.73
Fault: Water press. sensor
(signal too weak)
Water pressure sensor reports
that the water pressure is too
low
▶
Check: Water pressure, earth connection, cable, plug, water
pressure sensor (short circuit to GDN).
F.74
Fault: Water press. sensor
(signal too strong)
Water pressure too high
1.
Drain water.
2.
Check the water pressure sensor.
F.75
Fault: Pump/ water short-
age
Insufficient pressure jump de-
tected when starting the pump
1.
Check: Water pressure sensor, heating pump (blockage),
heating circuit (air, sufficient water volume), adjustable by-
pass, external expansion vessel (must be connected at the
return). Activate check programme P.0.
2.
If a low loss header or heating pipes with a diameter greater
than 1 1/2 inch are installed, replace the 3/4-inch seal in the
heating flow with a screen. If required, install the F.75 service
set.
F.77
Fault: Flue non-ret.
valve/condens. pump
No flue non-return flap feed-
back; condensate pump over-
flow
▶
Check: Cable to VR40 accessory, flue non-return flap (wiring,
feedback switch), condensate pump, bridge from the surface-
mounted thermostat, 2 in 7 multi-functional module (bridge).
F.78
Interrupt.: DHW outlet
sensor on ext. contr.
UK link box is connected
without the domestic hot water
temperature sensor being
bridged
1.
Check: Accessory (configuration/electrical connection).
2.
The unit displays a fault, but the unit has not malfunctioned.
F.80
Fault: actoSTOR inlet
sensor
Inlet temperature sensor defect-
ive or not connected
▶
Check (only in conjunction with F.91): NTC sensor, plug, cable
harness, PCB.
F.81
Fault: cylinder charging
pump
Cylinder is not fully charged
after specified time
▶
Check (only in conjunction with F.91): Cylinder charging
sensor, cylinder sensor, impeller sensor/limiter, prioritising
diverter valve, pump,
actoSTOR
pump (air), cable harness,
secondary heat exchanger (blockage).
F.82
Fault: Ext. current anode
External current anode defect-
ive or not connected
▶
Check: Cable harness, external current anode. If the external
current anode is not installed: Plug edge connector X43 with a
bridge into the PCB.
F.83
Fault: NTC temp. gradient
Temperature difference
between flow and return
temperature sensor is too small
▶
Check: Flow/return temperature sensor (function, correct
thermal connection), sufficient water volume.
F.84
Fault: NTC temp. diff. im-
plausible
Temperature difference is im-
plausible
▶
Check: Flow/return temperature sensor (correct thermal con-
nection, sensors are inverted).
F.85
Fault: NTCs fitted incor-
rectly
Flow/return temperat-
ure sensors returning
incorrect/implausible values
▶
Check: Flow/return temperature sensor (correct thermal con-
nection).
F.90
Fault: Communication
Communication with actoSTOR
interrupted
1.
Check: Plug, check cable harness to the
actoSTOR
module
(PEBus).
2.
If the product is to be operated without an
actoSTOR
: Set
D.092=0, if required, plug edge connector X31 into the BMU,
if required plug edge connector X1 into the actoSTOR.
F.91
Fault: actoSTOR sensor
Sensor on the actoSTOR is
defective
▶
Check: Plug, cable harness, sensor.
F.92
Fault: Incorrect gas type
The coding resistor on the PCB
does not match the gas group
that is entered
1.
Check: Coding resistor.
2.
Carry out the gas family check again and enter the correct
gas group.
F.93
Fault: Check gas route
Combustion quality outside the
permitted range
▶
Check: Gas injector (suitable for the gas group), flue gas re-
circulation, gas group, internal pressure measuring point in the
Venturi (blockage). Do not use any lubricants on the O-ring in
the Venturi.
F.94
Fault: Vortex and differen-
tial pressure
Sensors return implausible val-
ues.
▶
Check: Cable harness, plug, sensors.
