Baxi Performa Fault codes & diagnostics

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

Combi Natural Gas 24-28 kW 2001-2011 Discontinued
GC Number 47-393-07

Replaced by: Potterton Titanium

Download the Baxi Performa 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.
7 High 2 Medium 3 Low
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
47-393-07 Performa 28 2001–2011
Just want the most common Baxi Performa 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
1 red flash

Your boiler has likely stopped heating because the water inside has become too hot or the temperature sensors are reporting an incorrect reading.

High DIY-safe £90-180

What to check first

  1. Turn off the boiler at the electrical switch
  2. Wait 10 minutes for the unit to cool down
  3. Turn the selector switch to the 'Reset' position for five seconds and then back to the desired mode

Parts commonly replaced

  • NTC Temperature Sensor
  • Overheat Thermostat
  • Circulation Pump

Related codes

Full explanation for 1 red flash
2 red flashes

Your boiler has got too hot and has shut itself down as a safety precaution.

High DIY-safe £90-280

What to check first

  1. Check that all radiator valves are open and not turned off.
  2. Ensure your system water pressure is between 1 and 1.5 bar on the gauge.
  3. Turn the selector switch to the reset position for five seconds, then back to the desired mode.

Parts commonly replaced

  • Overheat Thermostat
  • Circulating Pump
  • Central Heating Return Filter

Related codes

Full explanation for 2 red flashes
3 green flashes

Your boiler has briefly lost its flame and is trying to restart itself automatically.

Medium DIY-safe £80-250

What to check first

  1. Monitor the boiler to see if it clears the fault and restarts automatically
  2. Check that other gas appliances in the home are working correctly
  3. If the fault persists and turns to red flashes, attempt a manual reset
  4. Ensure the condensate pipe has not frozen if the weather is extremely cold

Parts commonly replaced

  • Flame sensing electrode
  • Ignition lead
  • Gas valve

Related codes

Full explanation for 3 green flashes
3 red flashes

Your boiler has tried to light the gas five times without success and has now locked itself out for safety.

High DIY-safe £100-£250

What to check first

  1. Check that your credit or prepaid gas meter has sufficient funds.
  2. Ensure other gas appliances in your home, like a hob, are working correctly.
  3. Press and hold the reset button for five seconds to see if the boiler restarts.

Parts commonly replaced

  • Ignition Electrode
  • Gas Valve
  • Spark Generator

Related codes

Full explanation for 3 red flashes
4 green flashes

Your boiler is experiencing a brief communication hiccup between its internal electronic parts and should fix itself automatically.

Low DIY-safe £0-120

What to check first

  1. Wait for the boiler to complete its self-reset process
  2. If the lights continue to flash, turn the selector switch to the 'Reset' position for five seconds
  3. Ensure the power supply to the boiler is stable and not fluctuating

Parts commonly replaced

  • Printed Circuit Board (PCB)
  • Wiring Harness

Related codes

Full explanation for 4 green flashes
5 green flashes

Your boiler's internal computer has had a temporary communication glitch and is attempting to fix itself automatically.

Low DIY-safe £0-350

What to check first

  1. Wait for the boiler to complete its automatic self-reset process
  2. Turn the selector switch to the 'Reset' position for five seconds if the flashing continues
  3. Ensure the power supply to the boiler is stable and not fluctuating

Parts commonly replaced

  • Printed Circuit Board (PCB)

Related codes

Full explanation for 5 green flashes
5 red flashes

Your boiler's internal memory chip or main control board has developed a communication fault and cannot remember its settings.

High Engineer only £180-£350

Parts commonly replaced

  • Printed Circuit Board (PCB)
  • Parameter Storage Unit (PSU)
Full explanation for 5 red flashes
6 green flashes

Your boiler has experienced a temporary hiccup and should automatically restart itself shortly.

Low DIY-safe £0-80

What to check first

  1. Wait up to 15 minutes for the system to automatically reset
  2. Ensure your gas and electricity supplies are stable
  3. Turn the selector switch to the reset position and back if the lights persist

Parts commonly replaced

  • No parts usually required
  • Printed Circuit Board (PCB)

Related codes

Full explanation for 6 green flashes
6 red flashes

Your boiler has detected a general internal glitch or a sensor problem that is preventing it from running properly.

High Engineer only £100-280

Parts commonly replaced

  • Flow Temperature Sensor
  • Central Heating NTC Sensor
  • Main Control Board

Related codes

Full explanation for 6 red flashes
Digital codes
125

Your boiler has detected that water is not moving through the system properly, which is causing it to shut down to prevent overheating.

High DIY-safe £180-£350

What to check first

  1. Check that your system pressure is between 1 and 1.5 bar on the pressure gauge
  2. Ensure all radiator valves are fully open
  3. Bleed your radiators to remove any trapped air pockets

Parts commonly replaced

  • Circulation Pump
  • Primary Heat Exchanger (De-scaling)
  • Flow Temperature Sensor

Related codes

Full explanation for 125
432

Your boiler has detected an electrical safety issue where the system is not properly grounded.

Medium Engineer only £100-220

Parts commonly replaced

  • Wiring harness
  • Main PCB
  • Earthing wire

Related codes

Full explanation for 432
Status & diagnostic codes

1 operating states & engineer diagnostics

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

1 green flash Status Your boiler has reached its set temperature and is temporarily pausing its burner; this is a normal part of how the heating cycle works.