Viessmann Vitotwin 300-W - Page 135

135
Fault mes-
sage
Cause Remedy Re-
set-
ting
"319: Check
configura-
tion"
A fault is displayed after a
firmware update to indicate
that the system configuration
needs to be adjusted.
Reconfigure system.
Check code 5700
(Page 107), reset if necessa-
ry.
Check whether all connected
components (temperature
sensors, mixer extensions,
remote control unit etc.) have
been detected.
UR
"320: DHW
charging
sensor"
Cylinder temperature sensor
B3 faulty.
Check cylinder temperature
sensor (see page 140).
"332: BX 3
no function"
Fault in sensor B3: Plug not
inserted correctly.
Check connection (see
page 140).
"333: BX 4
no function"
Fault in sensor B4: Plug not
inserted correctly.
Check connection (see
page 140).
"334: BX 5
no function"
Fault in sensor B41: Plug not
inserted correctly.
"335: BX 21
no function"
Fault in extension kit, heating
circuit with mixer
Insert sensor in slot ?.
Check extension kit and con-
necting cable.
"336: BX 22
no function"
Sensor in extension kit heat-
ing circuit with mixer inserted
in the wrong position.
"337: B 1 no
function"
Fault, flow temperature sen-
sor, heating circuit 1: Plug not
inserted correctly.
Check connection (see
page 146).
"338: B 12
no function"
Fault, flow temperature sen-
sor, heating circuit 2: Plug not
inserted correctly.
"339: B 14
no function"
Fault, flow temperature sen-
sor, heating circuit 3: Plug not
inserted correctly.
"394: Eng
Bu BCU
Com fail"
Communication fault be-
tween the Stirling burner and
the control unit.
Check the cable to the gas
valve and replace gas valve
if necessary. If the fault has
not been rectified, replace
the control unit PCB (see
page 138).
AR
"395: Supp
Bu BCU
Com fail"
Communication fault be-
tween auxiliary burner and
control unit.
Troubleshooting
Fault messages
(cont.)
5618 294 GB
Service