Keston 86-CM-44 User, Installation And Servicing Instructions page 35

WD388/0/2004
ERROR CODES
Display Description of fault
E01 Ignition failure - the boiler has attempted to light five times and not succeeded -
check gas supply, air supply, flue, ignitor condition and spark gap.
E02 False flame - the unit is detecting a flame BEFORE ignition. Check gas valve
closure, power supply polarity and voltage and earth connection.
E03 Boiler overheat - check system for blockage, by-pass provision and pump
operation
E05 Fan failure - boiler cannot detect fan rotation. Check fan operation and BOTH
connectors onto fan.
E07 Flue overheat - check combustion and flue temperature vs. return temperature
(Installer numbers 7 and 3 above). The flue temperature should be no more
than 10C above return temperature. Possible heat exchanger fault
E08 Flame circuit error - possible control box fault..
E09 Valve drive error - possible gas valve or control box fault.
E10 Control box errors - possible faulty control box.
E11 The automatic test for calibration of flow and return sensors has failed. Check
both flow and return sensors are located on the correct pipes and are producing
the correct readings.
E12 to E22 Control box errors - possible faulty control box.
E23 Water filling error - check water pressure sensor.
E24 Water pressure lost 4 times in 24 hours - possible leak, check system and boiler.
E25 Control box errors - possible faulty control box.
E26 Flame signal lost 5 times in 4 minutes - The flame is unstable, check
combustion, gas supply, air supply and flue.
E30 Flow sensor short circuit - check connections to flow sensor
E31 Flow sensor open circuit - check connections to flow sensor are in place
E32 DHW sensor short circuit - check connections to DHW sensor
E33 DHW sensor open circuit - check connections to DHW sensor are in place
E34 Mains supply voltage < 180V - Check mains voltage system in dwelling
E35 Mains supply frequency incorrect - Check mains voltage system in dwelling
E37 Water pressure error - check system pressure and pressure sensor
E38 Reset key fault - replace fascia PCB
E40 Water pressure too high - check expansion vessel charge and operation
E41 Communication error between fascia and control box - check cables
E43 Return sensor short circuit - check connections to return sensor
E44 Return sensor open circuit - check connections to return sensor are in place
E45 Flue sensor short circuit - check connections to flue sensor
E46 Flue sensor open circuit - check connections to flue sensor are in place
E99 As E41
Installation & Servicing Instructions
Chapter 6 : Fault Finding The Keston C36 & C36P Combi Boilers
Page : 30