Fault Codes - Buderus 800-24 Installation And Servicing Instructions

5 Servicing
5.2

Fault codes

Code Meaning
1C
Flue gas thermostat (STB) has been tripped
Possible
cause
1 Water pressure is too low in the installation
2 Connection in cable harness defective or is getting too
hot
3 Flue gas thermostat if present is defective or is getting
too warm
Code Meaning
2C
Safety sensor exceeds 95 °C, blocked for 30 sec.
Possible
cause
1 Resistance in the installation is too high
2 Safety sensor is faulty
3 Problem with the pump or pump cabling
(no circulation)
4 Water pressure is too low in the installation
Code Meaning
2F
Temperature difference between the safety sensor and flow sensor is greater than or equal to 15 °K,
blocked for 30 sec.
Possible
cause
1 Resistance in the installation is too high
2 Safety sensor is dirty or faulty
3 Flow sensor is dirty or faulty
4 Problem with the pump or pump cabling
(no circulation)
5 Water pressure is too low in the installation
Subject to modifications resulting from technical improvements !
38 Installation and servicing instructions condensing gas boiler 800 - 24/29/43/60 and 800 - 24T25/29T25 H/V • edition 02/2006
Action
Top up the system (see subsection 2.1.1)
Check cable harness and press "reset" until "r" appears in
the display
Check the cable connections and press "reset" until "r"
appears in the display. Replace if necessary
Action
Check if not all (thermostatic) radiator valves are clogged
with dirt. Bypass is installed incorrectly
Measure if resistance over the sensor is correct.
If not replace safety sensor temporarily with another one
(see subsection 5.3.9 and subsection 5.3.10)
Check if the pump cabling is faulty or if the pump is stuck
(see subsection 5.3.7)
Top up the system (see subsection 2.1.1)
Action
Check if not all (thermostatic) radiator valves are closed or
clogged with dirt
Check the safety sensor for dirt. Measure if resistance over
the sensor is correct. If not replace safety sensor
temporarily with another one (see subsection 5.3.9 and
subsection 5.3.10)
Check the sensor, replace if necessary by temporarily
connecting another one (see subsection 5.3.9 and
subsection 5.3.10)
Check if the pump cabling is faulty or if the pump is stuck.
Replace pump if necessary (see subsection 5.3.7 and
subsection 5.3.8)
Top up the system (see subsection 2.1.1)
Buderus • http://buderus-domestic.co.uk