Vaillant aroSTOR VWL B 270/5 Installations- Und Wartungsanleitung Seite 80

Fault code Description
OVER PRESS. Overpressure inside the
heat pump
FREQ.DEFRO. Excessive de-icing
LOW PRES. Low pressure inside the
heat pump
OVER HEAT Domestic hot water over-
heating
(Water temperature
> 87 °C)
ANTI -BACT. Anti-legionella function in-
complete. Water-heating
could not be finished.
80
Possible cause
–
No water in the do-
mestic hot water cyl-
inder
–
Water temperature too
high (> 75 °C)
–
Water temperature
sensor removed from
the domestic hot water
cylinder
–
Water temperature
sensor defective
–
Air flow too low
–
Air inlet/outlet opening
blocked
–
Air pipe blocked
–
Pipeline too long or too
many elbows
–
Evaporator contamin-
ated
–
Air temperature sensor
missing from the air
flow
–
Air flow too low
–
Air inlet/outlet opening
blocked
–
Air pipe blocked
–
Fan blocked or defect-
ive
–
Evaporator contamin-
ated and blocked
–
Evaporator frozen
–
Air temperature sensor
missing from the air
flow
–
Water temperature
sensor defective
–
Water temperature
sensor removed from
the domestic hot water
cylinder
–
Water flow too high
–
Set target cylinder tem-
perature too high
–
Malfunction of the elec-
tric back-up heater
–
Use of the electric
back-up heater not au-
thorised
Solution
–
Checking that the
product is correctly
filled with water and
purged
–
Replacing the water
temperature sensor
–
Checking that the water
temperature sensor is
sitting correctly in the
cylinder dry pocket
–
Checking that the air
flows through the en-
tire pipework system
without any problems
–
Check the pipe length
–
Checking the status of
any filters present in
the air pipes
–
Checking that the
evaporator is free of
dust
–
Positioning the air tem-
perature sensor cor-
rectly
–
Checking that the fan is
running
–
Checking that the air
flows through the en-
tire pipework system
without any problems
–
Check the pipe length
–
Checking the status of
any filters present in
the air pipes
–
Checking that the
evaporator is free of
dust
–
Positioning the air tem-
perature sensor cor-
rectly
Checking that the sensor is
correctly positioned in the
pocket
–
Manually start the new
cycle for heating the
water
–
Reducing the target
cylinder temperature
–
Checking, cleaning or
replacing the electric
back-up heater
–
In the settings, au-
thorise the use of the
electric back-up heater
(e.g. for high-tariff peri-
ods)
Installation and maintenance instructions 8000015884_00
Temporary operation
Heat pump decommis-
sioned.
The reset must be imple-
mented manually.
Possible operation of the
back-up heater.
Heat pump decommis-
sioned.
The selected back-up
heater keeps the water
temperature at 38 °C.
Heat pump decommis-
sioned.
The selected back-up
heater keeps the water
temperature at 38 °C.
Heat pump decommis-
sioned.
Resetting is effected auto-
matically.
The product remains in
operation.