Ideal Independent Fault codes & diagnostics

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

Combi Natural Gas 24-30 kW 2011-2016 Discontinued

Replaced by: Logic

The Independent range comes in 4 types

Pick the one you have. The fault codes, GC numbers and manual differ by type.

Each model has its own manual A family spans several manuals, one per model or generation. Pick your model above and its page has the manual its fault codes were read from.

The fault code is already on your display

Note it down before pressing reset — resetting clears the code immediately. How to read fault codes →

Severity at a glance

Each cell = one fault code. Hover to identify.
2 Emergency 23 High 1 Medium 1 Low

All 27 documented codes

Tap any card for details

5 Boiler Resets in 15 minutes

Your boiler has shut itself down five times in a short period, which means the safety system is repeatedly blocking it from running to prevent potential damage or a safety hazard.

High Engineer only £150-350 Shared across the INDEPENDENT range

Parts commonly replaced

  • Printed Circuit Board (PCB)
  • Ignition Electrode
  • Gas Valve
  • Flame Sensor

Related codes

82

Your boiler is struggling because the electricity supply coming from your wall socket is too weak or unstable to run it correctly.

High Engineer only £100-250 Shared across the INDEPENDENT range

Parts commonly replaced

  • External fuse spur
  • Printed Circuit Board (PCB)
  • Wiring loom

Related codes

BCC Activation Fault

Your boiler's internal computer is struggling to communicate with a secondary plug-in component, preventing the system from starting safely.

High Engineer only £150-300 Shared across the INDEPENDENT range

Parts commonly replaced

  • Boiler Control Card (BCC)
  • Wiring harness

Related codes

BCC Fault

Your boiler is experiencing a communication error with its internal computer, meaning it cannot properly read its own programming and has safely shut down to prevent incorrect operation.

High Engineer only £150-300 Shared across the INDEPENDENT range

Parts commonly replaced

  • Boiler Control Card
  • Wiring harness

Related codes

Boiler Type Card Fault

Your boiler has lost the digital instructions telling it how to function, which prevents it from starting up correctly.

High Engineer only £150-250 Shared across the INDEPENDENT range

Parts commonly replaced

  • Boiler Interface Card
  • PCB

Related codes

c0

Your boiler's computer memory card is not being recognised, which prevents the system from starting up correctly.

High Engineer only £150-300 Shared across the INDEPENDENT range

Parts commonly replaced

  • BCC (Boiler Configuration Card)
  • Main PCB

Related codes

c2

Your boiler's computer memory card is not being recognised, meaning the system cannot run its operating programme.

High Engineer only £150-250 Shared across the INDEPENDENT range

Parts commonly replaced

  • Boiler Chip Card (BCC)
  • Main PCB

Related codes

F1

Your boiler has stopped working because the water pressure inside the system has dropped too low to operate safely.

High DIY-safe £80-150 Shared across the INDEPENDENT range

What to check first

  1. Locate the external filling loop, usually consisting of a small braided hose with one or two valves located underneath the boiler.
  2. Gradually open the valve(s) to allow mains water into the system while watching the pressure gauge on the front of the boiler.
  3. Stop filling once the needle reaches the green zone, typically between 1.0 and 1.5 bar, then ensure the valves are tightly closed.

Parts commonly replaced

  • Filling loop
  • Pressure relief valve
  • Expansion vessel

Related codes

F2

Your boiler was running but the flame has unexpectedly gone out, so it has safely shut down to prevent gas from building up.

High Engineer only £120-250 Shared across the INDEPENDENT range

Parts commonly replaced

  • Ignition electrode
  • Flame rectification probe
  • Gas valve

Related codes

F3

Your boiler is struggling to clear air and gases correctly, so it has safely shut itself down to prevent any unsafe operation.

High Engineer only £180-350 Shared across the INDEPENDENT range

Parts commonly replaced

  • Fan assembly
  • Wiring harness
  • Printed Circuit Board (PCB)

Related codes

Showing 11–20 of 27
F4

Your boiler has stopped working because it is unable to accurately measure the temperature of the water flowing through it, likely due to a faulty sensor.

High Engineer only £120-220 Shared across the INDEPENDENT range

Parts commonly replaced

  • Flow NTC Thermistor
  • Wiring harness

Related codes

F5

Your boiler has lost the ability to accurately measure the temperature of the water returning to it, so it has shut down to prevent potential overheating.

High Engineer only £120-200 Shared across the INDEPENDENT range

Parts commonly replaced

  • Return thermistor (NTC sensor)
  • Wiring harness

Related codes

F7

Your boiler is struggling because the electricity supply feeding it is unstable or dropping below the required level.

High Engineer only £120-250 Shared across the INDEPENDENT range

Parts commonly replaced

  • Printed Circuit Board (PCB)
  • Wiring harness
F9

Your boiler's main computer control panel is experiencing a software or internal communication error, meaning the boiler has safely shut down to prevent incorrect operation.

High Engineer only £250-450 Shared across the INDEPENDENT range

Parts commonly replaced

  • Printed Circuit Board (PCB)
  • Wiring harness

Related codes

False Flame Lockout

Your boiler has detected a flame when it shouldn't be burning, so it has safely shut itself off to prevent a potential hazard.

Emergency Engineer only £150-300 Shared across the INDEPENDENT range

Parts commonly replaced

  • Flame rectification probe
  • Gas valve
  • Printed Circuit Board (PCB)
Fan Fault

Your boiler has stopped working because it cannot properly circulate the air it needs for safe combustion.

High Engineer only £180-350 Shared across the INDEPENDENT range

Parts commonly replaced

  • Fan assembly
  • Wiring harness
  • Printed Circuit Board

Related codes

Flame Loss

Your boiler has detected that the flame inside has gone out unexpectedly and it cannot stay alight, so it has safely shut itself down to prevent gas from building up.

High Engineer only £150-350 Shared across the INDEPENDENT range

Parts commonly replaced

  • Ignition electrode
  • Gas valve
  • Condensate trap
  • Flame rectification probe

Related codes

Flow Thermistor

Your boiler's temperature sensor is providing faulty readings, causing the system to stop operating as it cannot safely monitor how hot the water is getting.

High Engineer only £120-220 Shared across the INDEPENDENT range

Parts commonly replaced

  • Flow NTC Thermistor
  • Wiring harness

Related codes

L1

Your boiler has detected that the water inside it has become dangerously hot or is not circulating correctly, so it has shut down to protect itself.

High Engineer only £120-250 Shared across the INDEPENDENT range

Parts commonly replaced

  • Pump
  • Diverter Valve
  • NTC Sensor

Related codes

L2

Your boiler has stopped working because it cannot light its internal flame, which is often caused by a frozen or blocked pipe that drains away waste water.

High Engineer only £120-250 Shared across the INDEPENDENT range

Parts commonly replaced

  • Condensate trap
  • Ignition electrode
  • Gas valve

Related codes

Showing 21–27 of 27
L5

Your boiler has attempted to restart itself too many times in a short period and has now locked itself out for safety.

High Engineer only £120-250 Shared across the INDEPENDENT range

Parts commonly replaced

  • Ignition electrode
  • Gas valve
  • Printed circuit board (PCB)
  • Flue seal

Related codes

L6

Your boiler has detected a flame inside the unit when it should be switched off, and it has safely locked itself to prevent further operation.

Emergency Engineer only £150-300 Shared across the INDEPENDENT range

Parts commonly replaced

  • Gas valve
  • Printed Circuit Board (PCB)
  • Flame rectification probe

Related codes

Low Mains Voltage

Your boiler is struggling because the electricity supply coming into your home is weaker than the level required to operate the unit safely.

Medium Engineer only £120-250 Shared across the INDEPENDENT range

Parts commonly replaced

  • PCB
  • Wiring harness
Low Water Pressure

Your boiler has stopped working because the amount of water inside the system has dropped below the required level.

High DIY-safe £80-120 Shared across the INDEPENDENT range

What to check first

  1. Locate the filling loop, which is usually a small silver braided hose or a built-in lever underneath the boiler.
  2. Slowly open the valve to let water enter the system until the pressure gauge on the front of the boiler reads between 1.0 and 1.5 bar.
  3. Close the valve tightly and check that the error code has cleared.

Parts commonly replaced

  • Pressure relief valve
  • Pressure gauge
  • Expansion vessel

Related codes

Outside Sensor Failure

Your boiler is struggling to detect the outdoor temperature, so it is running on a default setting instead of adjusting automatically to the weather.

Low Engineer only £120-200 Shared across the INDEPENDENT range

Parts commonly replaced

  • Outside temperature sensor
  • Wiring loom/connection
Return Thermistor

Your boiler's sensor is having trouble reading the temperature of the water returning to the unit, so it has stopped working to prevent potential overheating.

High Engineer only £120-200 Shared across the INDEPENDENT range

Parts commonly replaced

  • Return NTC Thermistor
  • Wiring harness

Related codes

Unconfigured PCB

The computer brain of your boiler has not been told which specific model it is installed in, so it cannot safely start the system.

High Engineer only £120-200 Shared across the INDEPENDENT range

Parts commonly replaced

  • Electronic Control Board (PCB)