Saunier Duval Opalia Fault codes & diagnostics

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

Natural GasLPG Discontinued

This boiler uses indicator light combinations

Note which lights are on, off, or flashing and at what speed. Match the combination to the cards below. Do not reset until you have noted the pattern. How to read fault codes →

Just want the most common Saunier Duval Opalia 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

LED / flash-pattern codes
Safety indicator (4) lights

Your boiler has detected a safety issue and has shut itself down to prevent any potential danger.

Emergency Engineer only £120-300

Parts commonly replaced

  • Flame rectification probe
  • Gas valve
  • Ignition lead
  • Printed Circuit Board (PCB)
Full explanation for Safety indicator (4) lights
Digital codes
Fault finding (Page 9 - 10)

The boiler documentation is incomplete and does not define the specific fault code, so the system remains in an unknown error state.

High Engineer only £120-250

Parts commonly replaced

  • Printed Circuit Board
  • Ignition Electrode
  • Gas Valve
Full explanation for Fault finding (Page 9 - 10)
Safety disconnection (General)

Your water heater has detected a safety issue and stopped working as a precaution because it cannot get the gas supply it needs to start.

High Engineer only £100-250

Parts commonly replaced

  • Gas valve
  • Ignition lead
  • Flame sensor
Full explanation for Safety disconnection (General)