Viessmann Vitotwin 300-W Installation And Service Instructions For Contractors page 128

Troubleshooting
Fault messages
Fault mes- Cause
sage
"270: Exc Excessive temperature dif-
temp diff h' ferential between the heating
exch" water flow and return.
"274: Zero Flow rate too low after filling.
flow protec-
tion"
"275: Zero Flow rate too low after vent-
flow aft dea- ing.
er"
"276: Zero Inadequate flow rate cap-
flow" tured in heating mode.
"278: Max Max flow temperature in-
temp rise" crease exceeded.
"280: Inner Generator base excess tem-
iron over- perature. Thermostat has re-
temp" sponded.
"281: Dyn Dynamic absorber overtravel
absorber switch actuated.
tripped"
128
(cont.)
Remedy
Check the system pressure.
Vent the heating system.
Check whether there is any
throughput (code 8366 in di-
agnostics heat generation)
Check function of the circula-
tion pump.
Check function of 3-way
diverter valve.
Check temperature sensors
and flow sensor.
Check connecting cables be-
tween Stirling engine and
control unit (cables to plug
X205).
Check temperature at bottom
of Stirling engine: max.
100 °C.
Check whether there is a
min. flow rate of 240 l/h (code
8366 in diagnostics heat gen-
eration).
Notify Viessmann Technical
Service.
Check plug-in connection
X205, connecting cables and
plugs to overtravel switches
at the bottom of the Stirling
engine (see page 152).
Check spring length; adjust if
necessary (see page 77).
Notify Viessmann Technical
Service if no fault can be dis-
covered or if unusual noises
can be heard.
Re-
set-
ting
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