Vaillant ecoTEC pro 24 Installation And Maintenance Instructions Manual page 37

Message
F.24 Safety switch-off: Temp.
incr. too fast
F.25 Safety switch-off: Flue
temp. too high
F.26 Fault: Fuel valve not
working
F.27 Safety switch-off: Flame
simulation
F.28 Start-up failure: Ignit.
unsuccessful
F.29 Operating failure: Ignit.
unsuccessful
F.32 Fault: Fan
F.49 Fault: eBUS
F.61 Fault: Fuel valve actu-
ation
F.62 Fault: Fuel valve switch-
off delay
F.63 Fault: EEPROM
F.64 Fault: Electronics/sensor
F.65 Fault: Electronics temp.
F.67 Fault: Electronics/flame
F.68 Fault: Flame signal un-
stable
F.70 Fault: Invalid Device
Specific Number
F.71 Fault: Flow sensor
F.72 Fault: Flow/return sensor
F.73 Fault: Water press.
sensor (signal too weak)
F.74 Fault: Water press.
sensor (signal too strong)
F.75 Fault: Pump/ water
shortage
0020244995_02 ecoTEC pro Installation and maintenance instructions
Possible cause
Temperature increase too fast
flue gas temperature too high
Gas valve assembly stepper
motor defective or not connec-
ted
Monitoring electrode reports an
incorrect flame
Failure during start-up or igni-
tion unsuccessful. Gas pressure
monitor or thermal cut-out has
been triggered.
Gas supply interrupted intermit-
tently. Re-ignition failed.
Fan defective or not connected
Undervoltage on the eBUS
The gas valve assembly cannot
be actuated
Delayed switch-off sequence for
the gas valve after the flame is
extinguished
EEPROM faulty
Electronics, safety-relevant
sensor or cable defective
Electronics defective or too hot
due to external influences
Implausible flame signal
Flame monitor reports an un-
stable flame signal
Incorrect/missing Device
Specific Number or
incorrect/missing coding resistor
Flow temperature sensor re-
turns implausible values
Temperature difference
between flow and return
temperature sensor is too great
Water pressure sensor reports
that the water pressure is too
low
Water pressure too high
Insufficient pressure jump de-
tected when starting the pump
Measure
▶
Check: Plug, cable to the heating pump, air/insufficient water
in the heating circuit, internal air vent (function), heating pump
(system pressure too low, temperature gradient too great on
heating flow, non-return valve). Activate check programme P.0.
▶
Check: Plug, safety cut-out plug, cable harness, cable to the
heating pump, internal air vent (function), flue gas route (block-
age, adverse wind conditions, flue pipework too long), insuf-
ficient water in heating circuit, heating pump, activate check
programme P.0.
▶
Check: Gas valve assembly stepper motor (plug, cable, pas-
sage for rinsing, voltage), multiple plug, cable harness.
▶
Check: Gas pressure at upper test opening, monitoring elec-
trode, PCB, gas solenoid valve.
▶
Check: Gas stopcock, gas flow pressure, gas valve assembly,
air intake pipe (blockage, loosened screw), condensate route
(blockage), multiple plug, cable harness, ignition transformer,
ignition cable, ignition plug, ignition electrode, monitoring elec-
trode, electronics, earthing, CO₂ setting.
▶
Check: Flue gas recirculation, condensate route (blockage),
earthing, cable to the gas valve assembly and electrode (loose
connection).
▶
Check: Plug, cable harness, fan (blockage, function, correct
speed), Hall sensor, PCB, flue gas route (blockage).
▶
Check: eBUS (overload, two power supplies with different po-
larities, short circuit).
▶
Check: Cable harness, plug, gas valve assembly (rinse), PCB.
▶
Check: Gas valve, surface of the burner (dirt), plug, cable har-
ness, PCB.
▶
Replace: PCB.
▶
Check: Flow sensor, cable to the sensor, flame recording
sensor (e.g. ionisation electrode) for an unstable signal,
electronics.
1. Check: PCB.
2. If required, reduce the environmental temperature.
▶
Check: Cable harness, flame monitor, PCB.
▶
Check: Air ratio, gas flow pressure, condensate route (block-
age), gas injector, ionisation flow (cable, electrode), flue gas
recirculation.
▶
If the display and PCB have been replaced, change the Device
Specific Number under D.93.
▶
Check: Flow temperature sensor (correct thermal connection).
▶
Check: Flow temperature sensor/return temperature sensor
(function, correct thermal connection).
▶
Check: Water pressure, earth connection, cable, plug, water
pressure sensor (short circuit to GDN).
▶
Check: Water pressure (heating side, when heating pump
is not active), drain water if required, cable, water pressure
sensor (short circuit to 24/5 V).
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.
Appendix
37