90 Installation and maintenance instructions 0020308118_05
Code/meaning Possible cause Measure
F.326
The hydraulic sensor and actu-
ator test has detected at least
two hydraulic components that
are not working.
3-port diverter valve defective or
blocked
▶ Check and, if required, replace the 3-port diverter valve.
Plug on 3-port motorised valve
loose/not plugged in
▶ Check the plug and the plug connection on the 3-port motor-
ised valve.
Interruption in the wiring har-
ness
▶ Check the wiring harness including all plug connections and, if
required, replace it.
Domestic hot water circuit not
connected
▶ Connect the domestic hot water circuit.
External pump runs continu-
ously
▶ Check the external pump and the system configuration.
The pump is defective. ▶ Check and, if required, replace the pump.
F.327
The minimum heating volume
flow is limited due to there be-
ing no domestic hot water cir-
cuit connected.
Cylinder bypass not connected ▶ Check the cylinder connection pipes.
Domestic hot water circuit
clogged/blocked
▶ Check the secondary heat exchanger for dirt.
F.330
The pump is not responding to
commands during the hydraulic
test.
Fault in the electrical connection
for the pump
▶ Check the wiring harness between the PCB and pump, includ-
ing all plug connections.
The pump is defective. ▶ Check and, if required, replace the pump.
F.334
The configuration of the flue
system was not completed.
Flue system configuration not
completed
▶ Check the flue gas configuration and complete this.
F.336
The unit is not permitted in this
configuration.
Flue system configuration set
incorrectly
▶ Set the approved flue system configuration.
Incorrect gas type set ▶ Check the gas type and the gas type setting under D.156 and
D.157.
F.337
The multiple-flue configuration
conversion set is not suitable
for the heat cell.
The multiple-flue configuration
conversion set is not suitable
for the heat cell
▶ Check and, if required, replace the conversion set comprising
air intake pipe with integrated non-return valve and air-mass
flow sensor.
F.338
Incorrect multiple-flue configura-
tion setting
Multiple-flue configuration set
incorrectly
▶ Set the approved flue system configuration.
F.342
The air-mass flow is not within
the permitted limits.
Fan speed does not correspond
to the target value
▶ Use D.033 and D.034 to check whether the fan speed deviates
by more than 20–30 rpm.
Plug on PCB loose/not plugged
in
▶ Check the plug and the plug connection.
Interruption in the wiring har-
ness
▶ Check the wiring harness including all plug connections and, if
required, replace it.
Plug for air-mass flow sensor
loose/not plugged in
▶ Check the plug and the plug connection for the air-mass flow
sensor.
You exit the measuring range
permanently. Air-mass flow
sensor defective
▶ Replace the entire air intake pipe.
Flue gas pipe blocked ▶ Check the entire flue gas pipe.
F.343
The signal for the air-mass flow
sensor is not plausible.
Plug for air-mass flow sensor
loose/not plugged in
▶ Check the plug and the plug connection for the air-mass flow
sensor.
Plug on PCB loose/not plugged
in
▶ Check the plug and the plug connection.
Interruption in the wiring har-
ness
▶ Check the wiring harness including all plug connections and, if
required, replace it.
Measurement discrepancy too
high. Air-mass flow sensor dirty.
▶ Check the air-mass flow sensor for dirt.
You exit the measuring range
permanently. Air-mass flow
sensor defective
▶ Replace the entire air intake pipe.
PCB defective ▶ Replace the PCB.
F.344
The control electrode can no
longer be used.
Transmission fault for calibra-
tion values
▶ Replace the control electrode (D.146, D.147).