Verified boiler fault code

Sime ALL 57 Fault Code (Brava Slim HE ErP)

Lock for the flow-temperature check (open-vent model).

Safety disclaimer

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Fault code summary

Manufacturer
Sime
Fault code
ALL 57
Fault type
Temperature sensor, Safety lockout
Severity
high
Reset
The official table directs technical assistance and a self-calibration procedure; no homeowner calibration or repeated reset is advised.
Applicable models
Brava Slim HE ErP 25, Brava Slim HE ErP 30, Brava Slim HE ErP 35, Brava Slim HE ErP 40

Quick answer

Lock for the flow-temperature check (open-vent model).

What does this fault code mean?

Lock for the flow-temperature check (open-vent model).

Common causes

  • Flow-temperature check lock

Symptoms

  • ALL 57 alarm displayed
  • Boiler operation may lock

What can the homeowner safely check?

  • Record the alarm and consult the user manual; do not access the flow sensor or control board.

Boiler reset information

The official table directs technical assistance and a self-calibration procedure; no homeowner calibration or repeated reset is advised.

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 verify delivery sensors, the gas valve, the board and the manufacturer calibration procedure.

Applicable boiler models

Related fault codes

Manufacturer documentation

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

Official manual fault table: | ALL | 57 | Lock for flow temperature (FT) check (open vent) |

Last verified

2026-09-12

Frequently asked questions

What does Sime ALL 57 mean?

Lock for the flow-temperature check (open-vent model).

Can I reset a Sime ALL 57 fault?

The official table directs technical assistance and a self-calibration procedure; no homeowner calibration or repeated reset is advised.