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
17
Fig. 14
Fault warning message 4F: Safety sensor temp. exceeds 100 °C
Flashing
Safety sensor temp. exceeds 100 °C
4
F
Yes
A
No
Check safety sensor
Fit the casing (page 48)
"reset"
600 Series 11S / 19S / 24S / 24C
OK
Check circulation pump (page 54)
New fault
warning message
4F
?
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 safety sensor
Replace circulation pump (page 54)
No
No
No
No
No
Yes
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"
Yes
Is at least one
thermostatic valve open (to
control the amount of water
circulating)?
Are all
maintenance shutoff
valves open?
Is the water
pressure in the system at
least 1 bar?
Safety sensor
OK?