Biasi E12 Fault Code (BASICA COND)

Safety disclaimer

Fault code summary

Manufacturer

Biasi

Fault code

E12

Fault type

Temperature sensor, Central heating

Severity

medium

Reset

No specific user reset is confirmed; arrange qualified diagnosis if the code remains.

Applicable models

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

Quick answer

Return NTC probe failure.

What does this fault code mean?

Return NTC probe failure.

Common causes

• Return NTC probe failure

Symptoms

• E12 shown on the LCD

What can the homeowner safely check?

• Record the code and do not disconnect or test the probe.

Boiler reset information

No specific user reset is confirmed; arrange qualified diagnosis if the code remains.

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 assess the return NTC probe, wiring and control board.

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: | E12+ | Return NTC probe failure |

Last verified

2026-09-12

Frequently asked questions