0020308118_05 Installation and maintenance instructions 93
Code/meaning Possible cause Measure
N.027
The signal for the temperature
sensor on the domestic hot wa-
ter connection is implausible.
Temperature sensor defective ▶ Check and, if required, replace the temperature sensor.
Short circuit in the connection
cable
1. Check whether the outlet temperature displayed under
D.003 is 116 °C.
2. Check the wiring harness including all plug connections and,
if required, replace it.
Interruption in the wiring har-
ness
1. Check whether the outlet temperature displayed under
D.003 is -13.5 °C.
2. Check the wiring harness including all plug connections and,
if required, replace it.
Domestic hot water connection
temperature sensor installed
incorrectly
▶ Check whether the temperature sensor on the domestic hot
water connection is correctly installed on the pipe.
N.032
The volume flow sensor is
defective or the signal is not
plausible.
Air in the system ▶ Purge the system.
Volume flow sensor defective ▶ Check and, if required, replace the volume flow sensor.
Bypass is blocked (only for
products with a bypass)
▶ Remove the blockage.
Air in the pump (only for
products with a bypass)
▶ Purge the system.
Pump defective (only for
products with a bypass)
▶ Replace the pump.
N.089
The installed heating pump
does not match the unit type.
Incorrect pump connected ▶ Check whether the pump that is connected is the one that is
recommended for the product.
N.095
The gas valve stepper motor
has reached the minimum per-
missible step number.
Fault in the flue gas route
caused by recirculation or flue
gas blockage
▶ Check the entire flue gas route.
Condensate discharge pipe
blocked
▶ Check the condensate discharge pipe.
Incorrect gas type set ▶ Check the gas type and the gas type setting under D.156 and
D.157.
Gas valve assembly offset in-
correctly stored in D.052 und
ggf. D.182
▶ Check the offset setting for the gas valve assembly.
Fault in the electrical connection
for the gas valve assembly
▶ Check and, if required, replace the wiring harness for the gas
valve assembly.
Gas valve assembly not elec-
trically connected/incorrectly
connected
▶ Check the electrical connection to the gas valve assembly.
Control electrode defective ▶ Check and, if required, replace the control electrode.
PCB defective ▶ Replace the PCB.
Air-mass flow sensor dirty or
defective (only in conjunction
with the conversion set compris-
ing the air intake pipe with in-
tegrated non-return valve and
air-mass flow sensor)
1. Check the air-mass flow sensor for dirt.
2. If required, replace the entire air intake pipe.
N.096
The gas valve stepper motor
has reached the maximum per-
missible step number.
Gas connection pressure too
low
▶ Check the gas connection pressure.
Incorrect gas type set ▶ Check the gas type and the gas type setting under D.156 and
D.157.
Gas valve assembly offset in-
correctly stored in D.052 und
ggf. D.182
▶ Check the offset setting for the gas valve assembly.
Fault in the electrical connection
for the gas valve assembly
▶ Check and, if required, replace the wiring harness for the gas
valve assembly.
Gas valve assembly not elec-
trically connected/incorrectly
connected
▶ Check the electrical connection to the gas valve assembly.
PCB defective ▶ Replace the PCB.
To Next Page
Loading...
Need help?
General
