Viessmann Vitotwin 300-W Installation And Service Instructions For Contractors page 135

Fault messages
Fault mes- Cause
sage
"319: Check A fault is displayed after a
configura- firmware update to indicate
tion" that the system configuration
needs to be adjusted.
"320: DHW Cylinder temperature sensor
charging B3 faulty.
sensor"
"332: BX 3 Fault in sensor B3: Plug not
no function" inserted correctly.
"333: BX 4 Fault in sensor B4: Plug not
no function" inserted correctly.
"334: BX 5 Fault in sensor B41: Plug not
no function" inserted correctly.
"335: BX 21 Fault in extension kit, heating
no function" circuit with mixer
"336: BX 22 Sensor in extension kit heat-
no function" ing circuit with mixer inserted
in the wrong position.
"337: B 1 no Fault, flow temperature sen-
function" sor, heating circuit 1: Plug not
inserted correctly.
"338: B 12 Fault, flow temperature sen-
no function" sor, heating circuit 2: Plug not
inserted correctly.
"339: B 14 Fault, flow temperature sen-
no function" sor, heating circuit 3: Plug not
inserted correctly.
"394: Eng Communication fault be-
Bu BCU tween the Stirling burner and
Com fail" the control unit.
"395: Supp Communication fault be-
Bu BCU tween auxiliary burner and
Com fail" control unit.
(cont.)
Remedy
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.
Check cylinder temperature
sensor (see page 140).
Check connection (see
page 140).
Check connection (see
page 140).
Insert sensor in slot ?.
Check extension kit and con-
necting cable.
Check connection (see
page 146).
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).
Troubleshooting
Re-
set-
ting
UR
AR
135