Ferroli Optimax HE Plus Fault codes & diagnostics

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

CombiSystem Natural Gas 18-35 kW 2009-2017 Discontinued
GC Numbers 41-267-3347-267-4447-267-45
Download the Ferroli Optimax HE Plus 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 →

Versions & GC numbers

Which version do you have?

The GC number on your boiler's data badge identifies the exact appliance and production years, as recorded in the UK Product Characteristics Database.

GC number Appliance (register name) Produced
41-267-33 Optimax HE Plus 35 S 2009–2017
47-267-44 Optimax HE Plus 31 C 2009–2017
47-267-45 Optimax HE Plus 38 C 2009–2017
Just want the most common Ferroli Optimax HE Plus faults?
The top 6 problems in plain English — with causes, DIY checks and repair costs.
Fault codes

All 3 documented codes

Tap any card for details

A47

Your boiler's water pressure sensor is providing an incorrect reading, which is preventing the system from heating your water correctly.

High Engineer only £120-220

Parts commonly replaced

  • Water pressure sensor
  • Wiring harness

Related codes

Full explanation for A47
Low system pressure

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

High DIY-safe £80-120

What to check first

  1. Locate the external filling loop, which is a flexible braided hose underneath the boiler.
  2. Open the valves at both ends of the hose to allow water into the system until the pressure gauge reads between 1 and 1.5 bar.
  3. Ensure both valves are tightly closed and check for any visible leaks on your radiators or pipework.

Parts commonly replaced

  • Filling loop
  • Pressure relief valve
  • Pressure gauge

Related codes

Full explanation for Low system pressure
No burner ignition

Your boiler is currently failing to light the flame it needs to produce heat and hot water.

High Engineer only £150-300

Parts commonly replaced

  • Ignition electrode
  • Gas valve
  • Printed Circuit Board

Related codes

Full explanation for No burner ignition
Status & diagnostic codes

1 operating states & engineer diagnostics

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

FH Status Your boiler is currently performing an automatic two-minute process to clear air from the system before it fires up.