Verified boiler fault code

Biasi E11 Fault Code (BASICA COND)

Parasite flame.

Safety disclaimer

Boiler repair help from Aza & Sons Services

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

Manufacturer documentation

Biasi BASICA COND user manual and installation instructions

SIGNAL 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.