Troubleshooting
6
26
Installation and service instructions RC20 room controller • Issue 08/2006
We reserve the right to make any changes due to technical modifications.
6
Troubleshooting
This fault table lists possible system faults such as EMS
component faults. As far as possible, the heating system remains
in operation in the case of a system fault, i.e. heat can still be
generated (albeit with an unfavourable operating point).
USER NOTE
Other faults are described in the documents relating to the
individual boiler.
Abbreviations used:
SC
= Service code
FC
= Fault code: turn the rotary selector to display it
SC
FC
Fault
Effects on control
characteristics
Possible cause
Remedy
A01
808
1)
DHW sensor
faulty
No domestic hot water is
produced.
Sensor connected or
mounted incorrectly.
Sensor cable broken or
short-circuited.
Sensor faulty.
Check sensor connection
and sensor cable.
Check mounting of sensor
on storage cylinder.
Compare resistance value
with sensor curve.
A01
810
1)
DHW remains
cold
The system constantly tries to
heat the hot water cylinder to
the hot water temperature
setting.
DHW priority is switched OFF
after the error message is
displayed.
Constant drawing or
system leak.
If necessary fix the leak.
Sensor connected or
mounted incorrectly.
Sensor cable broken or
short-circuited.
Sensor faulty.
Check sensor connection
and sensor cable.
Check mounting of sensor
on storage cylinder.
Compare resistance value
with sensor curve.
Charge pump connected
incorrectly or faulty.
Check operation of charge
pump.
A01
816
No
communication
with UBA 1/
UBA 3/MC10
Boiler not receiving heat
demands, heating system not
heating.
EMS bus system is
overloaded.
Reset by switching the
heating system off and then
on again.
If necessary inform your
local service centre.
UBA 1/UBA 3/MC10 is
faulty.
Tab. 4
Fault table (system faults)
1)
Not possible for operation on boilers with UBA 1.5.
