Viessmann D2RA, Installation Instructions For Contractors

Page: 96 / 164

96
Fault code dis-
played System characteristics Cause Measures
9E Control mode No flow rate in solar circuit
or flow rate too low, or
temperature limiter has re-
sponded. Check solar circuit pump and solar
circuit. Acknowledge fault mes-
sage.
9F Control mode Solar control module or
Vitosolic fault Replace solar control module or
Vitosolic.
A3 Burner blocked Flue gas temperature sen-
sor incorrectly positioned Fit flue gas temperature sensor
correctly (see page 107).
A7 Control mode with incorrect
time Programming unit faulty Replace the programming unit.
A8 Burner blocked. The venting
program is started automati-
cally (see page 43) Air in the secondary pump
or minimum flow rate not
achieved Vent the secondary circuit if the
fault message continues to be dis-
played.
A9 If a heating circuit with mixer
is connected, the burner op-
erates at its lower heating
output.
If only one heating circuit
without mixer is connected,
the burner is blocked. Secondary pump blocked Check secondary pump.
b0 Burner blocked Short circuit, flue gas tem-
perature sensor Check flue gas temperature sen-
sor.
b1 Control mode as per deliv-
ered condition Communication error, pro-
gramming unit Check connections; replace pro-
gramming unit if necessary.
b5 Control mode as per deliv-
ered condition Internal fault Replace control unit.
b7 Burner blocked Fault, coding card Plug in coding card or replace if
faulty.
b8 Burner blocked Lead break, flue gas tem-
perature sensor Check flue gas temperature sen-
sor.
bA Mixer regulates to 20 °C flow
temperature. Communication error, ex-
tension kit for heating cir-
cuit 2 (with mixer) Check extension kit connections
and code.
bb Mixer regulates to 20 °C flow
temperature. Communication error, ex-
tension kit for heating cir-
cuit 3 (with mixer) Check extension kit connections
and code.
bC Control mode without remote
control Communication error,
Vitotrol remote control,
heating circuit 1 (without
mixer) Check connections, cable, coding
address "A0" in the
"Heating cir-
cuit" group and remote control set-
tings (see page 148).
With wireless remote controls:
check connection; place remote
control close to the heat source.
bd Control mode without remote
control Communication error,
Vitotrol remote control,
heating circuit 2 (with mix-
er) Check connections, cable, coding
address "A0" in the
"Heating cir-
cuit" group and remote control set-
tings (see page 148).
With wireless remote controls:
check connection; place remote
control close to the heat source.
Troubleshooting
Fault codes
(cont.)
5678 044 GB
Diagnosis