Biasi E09 Fault Code (BASICA COND)

Safety disclaimer

Fault code summary

Manufacturer

Biasi

Fault code

E09

Fault type

Flue, Temperature sensor, Electrical

Severity

high

Reset

No unrestricted user reset is confirmed for this flue-sensor fault.

Applicable models

BASICA COND 24C, BASICA COND 28C, BASICA COND 32C

Quick answer

Flue-gas NTC probe interruption.

What does this fault code mean?

Flue-gas NTC probe interruption.

Common causes

• Flue-gas NTC probe interruption

Symptoms

• E09 shown on the LCD

What can the homeowner safely check?

• Record the code and check only for an obvious external flue obstruction without dismantling anything.

Boiler reset information

No unrestricted user reset is confirmed for this flue-sensor fault.

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 the flue-gas NTC probe, wiring and flue system.

Applicable boiler models

• BASICA COND 24C
• BASICA COND 28C
• BASICA COND 32C

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

SIGNAL DISPLAYED BY THE LCD: | E09+ | Flue gas NTC probe failure (interruption) |

Last verified

2026-09-12

Frequently asked questions