Troubleshooting
3
Subject to modifications resulting from technical improvements!
Buderus Ltd. • http://www.buderus-domestic.co.uk
Servicing manual for wall-mounted condensing gas boiler 600 Series 11S/19S/24S/24C • Issued 02/2006
13
Fig. 10
Fault warning message 4A: Feed sensor above 100 °C
Flashing
Feed sensor above 100 °C
4
A
Yes
16
No
Check circulation pump (page 54)
New fault warning message
4A
?
Circulation pump OK?
Remove the casing (page 48)
Open maintenance shutoff valves
Fill up with water as indicated in the
installation and servicing instruc-
tions, and purge the system of air
Open one thermostatic valve
Replace circulation pump (page 54)
No
No
No
No
Yes
Yes
Yes
Check system and heat exchanger, as
indicated in the installation and servicing
instructions, for signs of airlocks and
dirt - purge and/or clean as required.
"reset"
17
Yes
Filter to catch dirt fitted?
If yes, is it unclogged?
Is at least one
thermostatic valve open (to control
the amount of water cir-
culating)?
Are all
maintenance shutoff
valves open?
Is the water
pressure in the system at
least 1 bar?