Sime Format HE Combi Fault codes & diagnostics

7 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.

Combi Natural Gas 2004-2012 Discontinued
GC Numbers 47-719-2247-719-27
Download the Sime Format HE Combi manualThe official installation and service manual (PDF), the document these fault codes were read from. PDF

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Severity at a glance

Each cell = one fault code. Hover to identify.
2 Emergency 4 High 1 Medium

All 7 documented codes

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Boiler off

Your boiler is currently switched off or not receiving power, so it cannot provide heating or hot water.

High DIY-safe

What to check first

  1. Check that the boiler's power switch or plug is turned on.
  2. Check your home's fuse box or circuit breaker to ensure the boiler fuse hasn't tripped.
  3. Verify that your room thermostat and timer are turned on and calling for heat.

Parts commonly replaced

  • FUSE
  • PCB
  • Power Supply

Related codes

Fan fault

Your boiler has stopped working because it cannot detect that the internal fan, which safely removes combustion gases, is operating correctly.

High Engineer only £150-300

Parts commonly replaced

  • Flue gas fan
  • Air pressure switch
  • Printed Circuit Board (PCB)

Related codes

Ignition lock

Your boiler has stopped working because it failed to light the flame, and it has locked itself for safety with a red light showing.

High Engineer only £150-300

Parts commonly replaced

  • Ignition electrode
  • Gas valve
  • PCB

Related codes