Baxi Combi 80e Fault codes & diagnostics

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

Combi Natural Gas 24 kW 2001-2011 Discontinued
GC Numbers 47-075-1347-075-06

Replaced by: Baxi Duo-tec Combi

Download the Baxi Combi 80e manual The official installation & service manual (PDF) — the exact document these fault codes were verified against. PDF

This boiler uses LED flash patterns

Count the flashes in one repeating group before the pause. That number is your fault code. Do not reset until you have noted it. How to read fault codes →

Severity at a glance

Each cell = one fault code. Hover to identify.
12 High
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
47-075-13 Combi Instant 80 e 2003–2005
47-075-06 Combi 80 e 2001–2011

Appliance names and production years are taken from the UK Product Characteristics Database (the SAP/SEDBUK register). Where a GC number is also printed in this model's own manufacturer manual, both sources were checked to agree.

Just want the most common Baxi Combi 80e faults?
The top 6 problems in plain English — with causes, DIY checks and repair costs.
Fault codes

All 12 documented codes

Tap any card for details

LED / flash-pattern codes
neon flashing (Burner lights)

Your boiler is trying to start but cannot light the gas flame, meaning you will not have any heating or hot water.

High DIY-safe £120-350

What to check first

  1. Check that your gas emergency control valve is in the 'on' position
  2. If you have a prepaid gas meter, check that you have sufficient credit
  3. Check if other gas appliances in your home, like a hob, are working correctly
  4. Reset the boiler by turning the selector switch to the 'R' position for at least five seconds

Parts commonly replaced

  • Ignition Electrode
  • Gas Valve
  • Printed Circuit Board (PCB)
Full explanation for neon flashing (Burner lights)
neon flashing (Fan runs)

Your boiler has detected that the fan is spinning but not reaching the required speed to safely clear waste gases, preventing the burner from lighting.

High Engineer only £150-£350

Parts commonly replaced

  • Fan Assembly
  • Air Pressure Switch
  • Venturi Tube

Related codes

Full explanation for neon flashing (Fan runs)
neon flashing (Section D)

Your boiler is failing to clear its system of air before starting, so it has safely shut down to prevent ignition.

High Engineer only £150-250

Parts commonly replaced

  • Air pressure switch
  • Venturi
  • Fan assembly
  • Flue seals
Full explanation for neon flashing (Section D)
neon flashing (Section E)

Your boiler is failing to light the fuel inside even though it is trying to start, so it has safely shut itself down to prevent a gas build-up.

High Engineer only £150-300

Parts commonly replaced

  • Ignition PCB
  • Gas valve
  • Flame sensing electrode
Full explanation for neon flashing (Section E)
neon flashing (Section H & K)

Your boiler's internal computer has crashed or is struggling to process the reset command, preventing it from starting up again safely.

High Engineer only £150-300

Parts commonly replaced

  • Printed Circuit Board (PCB)
  • Control Knob Interface
Full explanation for neon flashing (Section H & K)
neon flashing (Section I)

Your boiler is lighting up but shutting off shortly after because it cannot confirm that the flame is staying on, meaning you currently have no heating or hot water.

High Engineer only £120-250

Parts commonly replaced

  • Flame rectification probe
  • Printed Circuit Board (PCB)
Full explanation for neon flashing (Section I)
neon flashing (Section J)

Your boiler has detected that it is running too hot and has automatically shut itself down to prevent damage.

High Engineer only £120-250

Parts commonly replaced

  • Overheat Thermostat
  • Pump
  • Diverter Valve
Full explanation for neon flashing (Section J)
neon flashing (Spark/Ignition)

Your boiler is failing to light the gas to create a flame, which means your heating and hot water will not work.

High DIY-safe £100-280

What to check first

  1. Check that your gas supply is turned on at the meter
  2. Turn the selector switch to the 'Reset' position and hold for 5 seconds
  3. Wait for the boiler to attempt to restart; if the light continues to flash, call a Gas Safe engineer

Parts commonly replaced

  • Ignition Electrode
  • Printed Circuit Board (PCB)
  • Gas Valve
Full explanation for neon flashing (Spark/Ignition)
Digital codes
Burner on neon NOT illuminated

Your boiler is not firing up because it isn't receiving the necessary signal or fuel to start the heating process.

High Engineer only £150-350

Parts commonly replaced

  • Gas valve
  • Printed Circuit Board (PCB)
  • Wiring harness
Full explanation for Burner on neon NOT illuminated
Flame Failure (Red Light) ON

Your boiler has tried to ignite but was unable to stay lit, meaning your heating and hot water will not work until it is reset or repaired.

High DIY-safe £100-280

What to check first

  1. Locate the selector switch on the front control panel
  2. Turn the switch to the 'R' (Reset) position and hold for 5 seconds
  3. Return the switch to its original position and check if the red light goes out

Parts commonly replaced

  • Gas Valve
  • Ignition Electrode
  • Flame Sensing Electrode
  • PCB
Full explanation for Flame Failure (Red Light) ON
Red 'Flame Failure' neon lit

Your boiler has attempted to light the gas burner multiple times but has failed to detect a flame, causing it to shut down for safety reasons.

High Engineer only £120-250

Parts commonly replaced

  • Ignition Electrode
  • Gas Valve
  • Printed Circuit Board
Full explanation for Red 'Flame Failure' neon lit
Reset neon illuminated (Red)

Your boiler has detected an internal error and has entered a lock-out state, meaning it has switched itself off to prevent damage.

High Engineer only £150-350

Parts commonly replaced

  • Printed Circuit Board (PCB)
  • Selector Switch
  • Ignition Electrode
Full explanation for Reset neon illuminated (Red)