128
Displayed
fault code
System characteris-
tics
Cause
Measures
A4
Control mode
Max. system pres-
sure exceeded
Check system pressure.
Check the function and
sizing of the expansion
vessel.
Vent the heating system.
Coding address "0E" is
set to "1" to document the
fault. Must be manually
reset to "0" after trouble-
shooting.
A7
Control mode as per
delivered condition
Programming unit
faulty
Replace programming
unit
A8
Burner blocked The
venting program is
started automatically
(see page 85)
Air lock in the inter-
nal circulation
pump or minimum
flow rate not ach-
ieved
Vent the system if the fault
message continues to be
displayed
A9
If a heating circuit
with mixer is connec-
ted, the burner oper-
ates at its lower heat-
ing output.
If only one heating
circuit without mixer
is connected, the
burner is blocked.
Internal circulation
pump blocked
Check the circulation
pump
b0
Burner blocked
Short circuit, flue
gas temperature
sensor
Check flue gas tempera-
ture sensor
b1
Control mode as per
delivered condition
Communication er-
ror, programming
unit
Check connections and
replace programming unit
if required
b4
Controls as if the out-
side temperature
were 0 °C
Internal fault
Replace the control unit
b5
Control mode as per
delivered condition
Internal fault
Replace the control unit
b7
Burner blocked
Boiler coding card
faulty
Plug in or replace boiler
coding card
Troubleshooting
Fault codes
(cont.)
5773 238 GB
Содержание B2UA
Страница 10: ...10 13 14 15 Preparing for installation Preparing the installation cont 5773 238 GB ...
Страница 11: ...11 16 Preparing for installation Preparing the installation cont 5773 238 GB Installation ...
Страница 12: ...12 sF 17 19 21 20 18 Preparing for installation Preparing the installation cont 5773 238 GB ...
Страница 13: ...13 24 22 23 Preparing for installation Preparing the installation cont 5773 238 GB Installation ...
Страница 14: ...14 27 26 25 Preparing for installation Preparing the installation cont 5773 238 GB ...
Страница 15: ...15 28 2x 2x 29 30 Preparing for installation Preparing the installation cont 5773 238 GB Installation ...
Страница 21: ...21 Removing the front panels 2 4 2x 1 3 5 Installation sequence Installing the boiler 5773 238 GB Installation ...
Страница 22: ...22 Siting and levelling the boiler 1 2 SW17 Installation sequence Installing the boiler cont 5773 238 GB ...
Страница 29: ...29 2x 4x 4 3 5 2 1 Installation sequence Opening the control unit casing 5773 238 GB Installation ...
Страница 39: ...39 5 4 2 6 2x 3 1 Installation sequence Closing the control unit casing 5773 238 GB Installation ...
Страница 41: ...41 2x 1 4 2 3 5 Installation sequence Fitting the front panels 5773 238 GB Installation ...
Страница 185: ...185 0010 0004 0001 0003 0004 0005 0009 0006 0007 0008 0007 0002 Parts lists Cylinder module cont 5773 238 GB Service ...
Страница 199: ...199 5773 238 GB ...