Vaillant ecoTEC pro Installation And Maintenance Instructions Manual - page 35
Appendix
0020209589_01 ecoTEC pro Installation and maintenance instructions
35
Status code
Meaning
S.26
DHW mode: Fan overrun
S.27
DHW mode: Pump overrun
S.28
Hot water burner anti-cycling time
Others
S.30
Room thermostat (RT) is blocking heating
mode
S.31
Summer mode active or no heat requirement
from eBUS controller
S.32
Waiting period because of fan speed devi-
ation
S.34
Frost protection mode active
S.37
Waiting time: Fan failure in operation
S.39
"Burner off contact" has responded (e.g. con-
tact thermostat or condensate pump)
S.41
Water pressure > 2.8 bar
S.42
Flue non-return flap return signal blocks
burner operation (only in connection with VR
40 accessories) or condensate pump faulty,
heat requirement is blocked
S.46
Comfort protection mode, flame loss at min-
imum load
S.53
Product is within the waiting period of the
modulation block/operation block function
as a result of low water pressure (flow/return
spread too large)
S.54
Product is within the waiting period of the
operation blocking function as a result of low
water pressure (temperature gradient)
S.57
Waiting period, comfort safety mode
S.58
Modulation limitation due to noise/wind
S.76
System pressure too low. Top up water.
S.96
Return sensor test running, heating demands
are blocked.
S.97
Water pressure sensor test running, heating
demands are blocked.
S.98
Flow/return sensor test running, heating de-
mands are blocked.
C
Overview of fault codes
Code
Meaning
Cause
F.00
Flow temperature sensor interruption
NTC plug not plugged in or has come loose, multiple plug on the PCB
not plugged in correctly, interruption in cable harness, NTC defective
F.01
Return temperature sensor interruption
NTC plug not plugged in or has come loose, multiple plug on the PCB
not plugged in correctly, interruption in cable harness, NTC defective
F.10
Flow NTC short circuit
NTC defective, short circuit in cable harness, cable/casing
F.11
Return NTC short circuit
NTC defective, short circuit in cable harness, cable/casing
F.20
Safety switch-off: Temperature limiter
Incorrect earth connection between cable harness and product, flow or
return NTC defective (loose connection), black discharge via ignition
cable, ignition plug or ignition electrode
F.22
Safety switch-off: Low water pressure
No or insufficient water in the product, water pressure sensor defective,
cable to pump or water pressure sensor loose/not connected/defective
F.23
Safety switch-off: Temperature difference
too great
Pump blocked, insufficient pump output, air in product, flow and return
NTC connected the wrong way round
F.24
Safety switch-off: Temperature rise too fast
Pump blocked, insufficient pump output, air in product, system pressure
too low, non-return valve blocked/incorrectly installed