Verified boiler fault code
Biasi E11 Fault Code (BASICA COND)
Parasite flame.
Safety disclaimer
Fault code summary
- Manufacturer
- Biasi
- Fault code
- E11
- Fault type
- Flame detection, Safety lockout
- Severity
- high
- Reset
- No unrestricted user reset is confirmed; arrange qualified diagnosis if the code persists.
- Applicable models
- BASICA COND 24C, BASICA COND 28C, BASICA COND 32C
Quick answer
Parasite flame.
What does this fault code mean?
Parasite flame.
Common causes
- Parasite flame
Symptoms
- E11 shown on the LCD
What can the homeowner safely check?
- Record the code and do not access the burner or flame-detection components.
Boiler reset information
No unrestricted user reset is confirmed; arrange qualified diagnosis if the code persists.
When should I call an engineer?
Contact a suitably qualified heating engineer when the fault persists, the boiler locks out, or the manufacturer instructions do not resolve it. For gas appliance work in the UK, use a Gas Safe registered engineer.
Engineer diagnosis
- A qualified engineer should investigate flame detection, gas-valve closure and control electronics.
Applicable boiler models
Related fault codes
- E01 — BASICA COND
Safety lockout due to failed ignition.
Read fault code - E02 — BASICA COND
Lockout due to the safety thermostat.
Read fault code - E03 — BASICA COND
EEPROM error.
Read fault code - E04 — BASICA COND
Pump circulation failure or insufficient system pressure.
Read fault code - E05 — BASICA COND
Fan-control anomaly.
Read fault code - E06 — BASICA COND
Heating NTC probe failure.
Read fault code - E07 — BASICA COND
DHW NTC probe failure.
Read fault code - E08 — BASICA COND
External NTC probe failure.
Read fault code
Manufacturer documentation
Biasi BASICA COND user manual and installation instructionsSIGNAL DISPLAYED BY THE LCD: | E11+ | Parasite flame |
Last verified
2026-09-12
Frequently asked questions
What does Biasi E11 mean?
Parasite flame.
Can I reset a Biasi E11 fault?
No unrestricted user reset is confirmed; arrange qualified diagnosis if the code persists.