Servicing
5
Installation and maintenance instructions for wall-mounted condensing gas boiler 600 - 28C • 01/2004
45
Subject to modifications resulting from technical improvements!
Boulter Buderus Ltd. • http://www.boulter-boilers.com
Code
Meaning
CU; CY
Blinking fault code
: Short circuit in return sensor or interrupted
Possible
cause
Action
1
Wiring and connections of the return sensor may be
faulty
Check wiring and connections of the return sensor
2
Return sensor may be faulty
Check return sensor and replace when necessary
Code
Meaning
E1
;
A
;
C
;
F
;
H
;
L
;
Y
Non blinking fault code
: Internal UBA error
Possible
cause
Action
1
Regulating device may have to cope with interference
– Check if for example induction fields interfere with the
regulating device
– Check if the are any peaks in the electrical network
caused by maybe windmills or a power generator
2
UBA may be defective
– Press reset. If fault code remains then try to temporarily
connect a different UBA (see subsection 5.3.2)
– Check if UBA 3 is correctly mounted
(see subsection 5.3.2)
Code
Meaning
H07
Non blinking fault code
: System pressure too low
Possible
cause
Action
1
System pressure too low
Top up the system (see subsection 2.1.1)
2
Pressure sensor may be defect
Check the pressure sensor
Problem
:
No DHW, despite the system being operational
– Check three-way valve replace when necessary
– Check DHW sensor and replace when necessary
Problem
:
No heating, despite that there is a demand for heat and the boiler is operational
– Check regulating device configuration and/ or the wiring
– Check the wiring between the regulating device and the UBA
– Check all the wiring
– Check the UBA and replace when necessary (see subsection 5.3.2)
