Biasi Gaia Fault codes & diagnostics

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

Combi Natural GasLPG 24-28 kW 1997-2002 Discontinued
GC Numbers 47-970-0847-970-09

Replaced by: Riva Advance

Download the Biasi Gaia 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
47-970-08 Savio Gaia 424S 1997–2002
47-970-09 Savio Gaia 428S 1997–2002
Just want the most common Biasi Gaia 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

Boiler ON (green) light off

Your boiler has lost power completely, meaning it will not turn on or provide any heating or hot water.

High DIY-safe £90-250

What to check first

  1. Check if other appliances in your home have power
  2. Check your main property fuse box to see if a circuit has tripped
  3. Ensure the boiler's power switch on the wall (fused spur) is turned on

Parts commonly replaced

  • Internal F1 or F2 glass fuses
  • Main Control PCB
  • External Fused Spur
Full explanation for Boiler ON (green) light off
Lock lamp / lock state

Your boiler has entered a safety lockout mode and stopped working because it failed to light or stay lit through several attempts.

High DIY-safe £100-280

What to check first

  1. Check that your gas supply is active and other gas appliances are working
  2. Locate the reset button or selector switch on the control panel
  3. Turn the selector to the 'R' (Reset) position for 2 seconds and then back to the on position

Parts commonly replaced

  • Ignition electrode
  • Flame sensing electrode
  • Gas valve
  • Pcb
Full explanation for Lock lamp / lock state
Lockout lamp (red) on

Your boiler is trying to light but cannot successfully create or detect a flame, causing it to shut down for safety.

High DIY-safe £120-£350

What to check first

  1. Check that your gas supply is turned on at the meter
  2. Check if other gas appliances (like a hob) are working
  3. Press the reset button to attempt a restart

Parts commonly replaced

  • Ignition electrode
  • Flame detection probe
  • Gas valve
  • PCB
Full explanation for Lockout lamp (red) on