ERROR CODES
As E41
E99
Flue sensor open circuit - check connections to flue sensor are in place
E46
Flue sensor short circuit - check connections to flue sensor
E45
Return sensor open circuit - check connections to return sensor are in place
E44
Return sensor short circuit - check connections to return sensor
E43
Communication error between fascia and control box - check cables
E41
Water pressure too high - check expansion vessel charge and operation
E40
Reset key fault - replace fascia PCB
E38
Water pressure error - check system pressure and pressure sensor
E37
Mains supply frequency incorrect - Check mains voltage system in dwelling
E35
Mains supply voltage < 180V - Check mains voltage system in dwelling
E34
DHW sensor open circuit - check connections to DHW sensor are in place
E33
DHW sensor short circuit - check connections to DHW sensor
E32
Flow sensor open circuit - check connections to flow sensor are in place
E31
Flow sensor short circuit - check connections to flow sensor
E30
Flame signal lost 5 times in 4 minutes - The flame is unstable, check
combustion, gas supply, air supply and flue.
E26
Control box errors - possible faulty control box.
E25
Water pressure lost 4 times in 24 hours - possible leak, check system and boiler.
E24
Water filling error - check water pressure sensor.
E23
Control box errors - possible faulty control box.
E12 to E22
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.
E11
Control box errors - possible faulty control box.
E10
Valve drive error - possible gas valve or control box fault.
E09
Flame circuit error - possible control box fault..
E08
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
E07
Fan failure - boiler cannot detect fan rotation. Check fan operation and BOTH
connectors onto fan.
E05
Boiler overheat - check system for blockage, by-pass provision and pump
operation
E03
False flame - the unit is detecting a flame BEFORE ignition. Check gas valve
closure, power supply polarity and voltage and earth connection.
E02
Ignition failure - the boiler has attempted to light five times and not succeeded -
check gas supply, air supply, flue, ignitor condition and spark gap.
E01
Description of fault
Display
WD388/0/2004
Chapter 6 : Fault Finding
The Keston C36 & C36P Combi Boilers
Installation & Servicing Instructions
Page : 30
