| Error Code | Possible fault |
|---|---|
| E09 | Gas valve connection cable |
| E10 | External probe fault |
| E12 | Differential water flow switch fault (still open) |
| E13 | Differential water flow switch fault (still closed) |
| E15 | Gas valve command fault |
| E20 | Central heating NTC fault |
| E28 | Flue NTC fault |
| E40 | Central heating return NTC fault |
| E50 | DHW NTC sensor fault (tank boiler) (s.c.) OR DHW NTC sensor fault (tank boiler) (o.c.) |
| E83/E84/E85/E86/E87 | No communication |
| E109 | Pre-circulation fault |
| E110 | i) Boiler max temperature exceeded for gradient (probable pump jammed or air in the circuit). OR ii) Boiler max temperature exceeded for overtemperature (probable pump jammed or air in the circuit). OR iii) Safety thermostat sensor tripped |
| E118 | Primary system water pressure too low (< 0.5=””> |
| E125 | Circulation fault (primary) |
| E128 | Frequent flame failure (12 times) |
| E129 | Safety error for frequently loss of flame with max correction during the ignition during Calibration Function |
| E130 | Flue thermostat sensor tripped (lockout) |
| E133 | Failure to light (could be a gas supply issue). Check that the gas supply is available. If possible try lighting a gas cooker or fire. |
| E134 | Elapsed time gas valve open without gas (short request in a short period) |
| E135 | Interuption of gas supply (internal error) |
| E154 | Flow/return sensor temperature test |
| E160 | Fan or fan wiring fault |
| E163 | Domestic Hot Water NTC sensor fault (s.c.) OR Domestic Hot Water NTC sensor fault (o.c.) |
| E270 | Circulation fault (dry fire) |
| E317 | Wrong power supply electrical frequency (Hz) |
| E321 | Hot water NTC fault |
| E384 | False flame |
| E385 | Under voltage |
| E430 | Water pressure temporary test |
| E430 + Flame ‘crossed’ | Water pressure test failed |
Potterton Assure Combi Boiler Error Codes
Assure Combi Boiler Error Codes