Verified boiler fault code

Sime ALL 93 Fault Code (Brava Slim HE ErP)

Combustion set cannot be reached error.

Safety disclaimer

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Fault code summary

Manufacturer
Sime
Fault code
ALL 93
Fault type
Combustion, Flue, Gas valve
Severity
high
Reset
The official table gives engineer checks; no user reset is confirmed.
Applicable models
Brava Slim HE ErP 25, Brava Slim HE ErP 30, Brava Slim HE ErP 35, Brava Slim HE ErP 40

Quick answer

Combustion set cannot be reached error.

What does this fault code mean?

Combustion set cannot be reached error.

Common causes

  • Electrical/electrode issue
  • Flue/outlet issue
  • Air-diaphragm issue on applicable balanced-flue models
  • Gas-calibration issue

Symptoms

  • ALL 93 alarm displayed

What can the homeowner safely check?

  • Do not adjust gas, air or combustion components; arrange qualified service.

Boiler reset information

The official table gives engineer checks; no user reset is confirmed.

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 electrical system, electrode, outlets, air diaphragm where applicable and gas calibration.

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 | 93 | Combustion set cannot be reached error |

Last verified

2026-09-12

Frequently asked questions

What does Sime ALL 93 mean?

Combustion set cannot be reached error.

Can I reset a Sime ALL 93 fault?

The official table gives engineer checks; no user reset is confirmed.