Ferroli Optimax HE 31 C Fault codes & diagnostics

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

CombiSystem Natural Gas 31 kW 2008-2015 Discontinued
GC Numbers 41-267-2647-267-42

Replaced by: Ferroli Modena HE

Download the Ferroli Optimax HE 31 C manual The official installation & service manual (PDF) — the exact document these fault codes were verified against. PDF

The fault code is already on your display

Note it down before pressing reset — resetting clears the code immediately. How to read fault codes →

All 5 documented codes

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A16

Your boiler is unable to safely control the flow of gas required to light the burner, so it has shut down to prevent any unsafe operation.

High Engineer only £200-350

Parts commonly replaced

  • Gas valve
  • PCB

Related codes

F07

Your boiler has detected an issue with the airflow system, which prevents it from firing up safely to provide heating or hot water.

High Engineer only £150-350

Parts commonly replaced

  • Fan unit
  • Air pressure switch
  • Flue seals
  • Venturi

Related codes

F24

Your boiler is struggling to clear exhaust gases because the fan component, which helps vent the system, is not receiving power or is failing to start.

High Engineer only £180-350

Parts commonly replaced

  • Fan assembly
  • Wiring harness
  • PCB (Printed Circuit Board)

Related codes

Low system pressure

Your boiler has stopped working because the water pressure inside your heating system has dropped too low to operate safely.

High DIY-safe

What to check first

  1. Locate the external filling loop, usually a small braided metal hose connecting two pipes under the boiler
  2. Open the valves at both ends of the hose to allow mains water to enter the system while watching the pressure gauge
  3. Close both valves firmly once the needle sits between 1 and 1.5 bar
  4. Reset the boiler using the reset button on the control panel

Parts commonly replaced

  • Filling loop
  • Pressure relief valve
  • Expansion vessel

Related codes

No burner ignition

Your boiler is failing to light the flame needed to heat your water and home.

High Engineer only £120-250

Parts commonly replaced

  • Ignition electrode
  • Gas valve
  • PCB

Related codes

1 operating states & engineer diagnostics

Not faults — these are normal operating states. Tap to expand.