Verified boiler fault code

Sime ALL 01 Fault Code (Brava Slim HE ErP)

Flue-gas thermostat fault.

Safety disclaimer

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Fault code summary

Manufacturer
Sime
Fault code
ALL 01
Fault type
Flue, Temperature sensor, Safety lockout
Severity
high
Reset
The official table directs the user to the technical assistance centre; no user reset is confirmed for this alarm.
Applicable models
Brava Slim HE ErP 25, Brava Slim HE ErP 30, Brava Slim HE ErP 35, Brava Slim HE ErP 40

Quick answer

Flue-gas thermostat fault.

What does this fault code mean?

Flue-gas thermostat fault.

Common causes

  • Flue-gas thermostat fault

Symptoms

  • ALL 01 alarm displayed

What can the homeowner safely check?

  • Record the complete alarm shown and consult the user manual; do not open the boiler.

Boiler reset information

The official table directs the user to the technical assistance centre; no user reset is confirmed for this alarm.

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 thermostat and associated safety circuit.

Applicable boiler models

Related fault codes

Manufacturer documentation

Brava Slim HE ErP installation, use and maintenance manual (official Sime document 6322841C)

Official manual alarm table: | ALL | 01 | Termóstato de gases |

Last verified

2026-09-12

Frequently asked questions

What does Sime ALL 01 mean?

Flue-gas thermostat fault.

Can I reset a Sime ALL 01 fault?

The official table directs the user to the technical assistance centre; no user reset is confirmed for this alarm.