What does the Sime AL 06 fault code mean?

Your boiler is not detecting a flame, which means it cannot light itself to provide heating or hot water.

How much does it cost to fix Sime error code AL 06?

Typical repair cost for the Sime AL 06 fault is £120-280 including labour.

Check if other gas appliances in your home, such as a hob, are working to confirm gas supply.

Manufacturer manual

No flame detection — check electrode integrity; verify gas availability and pressure; check gas valve operation

From this model's manual

Verified against the Sime Format Dgt He Combi installation & service manual, page 27.

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

Boiler cover options

A cover plan would handle faults like AL 06: no call-out fees, no surprise bills.

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Almost always a stuck diverter valve on combis.

Lockout fault with a reset-needed pattern.

Older boilers — thermocouple, draught, gas supply.