Code Description Action
29 Incorrect tacho signal from fan Check wiring to fan. If wiring OK replace fan.
30 Flow/return temperature differential too high Check no air in system or boiler
Check adequate ow of water through boiler
31 Flow thermistor short circuit Check wiring
Disconnect terminals from thermistor & conrm short
circuit using meter
Replace thermistor
32 Return thermistor short circuit Check wiring
Disconnect terminals from thermistor & conrm short
circuit using meter
Replace thermistor
33 Tank sensor short circuit Not tted check parameter 46 settings
35 Flue thermistor short circuit Check wiring
Disconnect terminals from thermistor & conrm short
circuit using meter
Replace thermistor
36 Flow thermistor open circuit Check wiring
Disconnect terminals from thermistor & conrm open
circuit using meter
Replace thermistor
37 Return thermistor open circuit Check wiring
Disconnect terminals from thermistor & conrm open
circuit using meter
Replace thermistor
38 Tank sensor open circuit Not tted check parameter 46 settings
40 Flue thermistor open circuit Check wiring
Disconnect terminals from thermistor & conrm open
circuit using meter
Replace thermistor
44 Internal Failure Check wiring harness & connections
If wiring OK replace control module
52 Flue gas temperature too high Check no air in system or boiler
Check adequate ow of water through boiler
60 Error reading parameters
Press reset. If fault keeps re-occuring replace control module.
61 Air pressure switch closed when it should be open Check for blockages in air pressure switch sensing pipes
Check air pressure switch and replace if necessary
107 Heat exchanger thermistor short circuit Check wiring
Disconnect terminals from thermistor & conrm short
circuit using meter
108 Heat exchanger thermistor open circuit Check wiring
Disconnect terminals from thermistor & conrm open
circuit using meter
Replace thermistor
109 Heat exchanger temperature too high Check no air in system or boiler
Check adequate ow of water through boiler
110 Heat exchanger temperature too low Check no air in system or boiler
Check adequate ow of water through boiler
111 Heat exchanger to return temperature differential too high Check no air in system or boiler
Check adequate ow of water through boiler
112 Heat exchanger temperature rise too fast Check no air in system or boiler
Check adequate ow of water through boiler
113 No valid mains frequency detected Check power supply to boiler
114 Invalid or conicting cascade address
Press reset. If fault keeps re-occuring replace control module.
115 Internal error Check wiring harness & connections
If wiring OK replace control module
MASTER AND SLAVE BOILER CONTROL MODULE ERROR CODES CONTINUED