Common problems guide

The most common Ideal Independent C24 problems

The faults most likely to send a Ideal Independent C24 into lockout — with plain-English causes, what to check first, estimated repair costs and whether you need a Gas Safe engineer.

This model is discontinued. Parts can be harder to source and expensive. If repair costs are mounting, a new A-rated boiler may be the smarter choice.

The 5 most common faults

01

L2 High Engineer

Your boiler has detected that it is getting too hot or cannot move water through the system, so it has safely shut itself down to prevent damage.

Est. cost: £120-250
Parts: Central heating pump, Flow sensor, NTC thermistor

Full guide for L2

02

L1 High Engineer

Your boiler has lost communication with its internal memory chip, meaning it cannot operate safely until the settings are restored or the component is replaced.

Est. cost: £150-300
Parts: Boiler Control Card (BCC), Wiring Harness

Full guide for L1

03

None High Engineer

Your boiler is struggling to accurately measure the temperature of the water being heated, which is preventing it from running your heating and hot water properly.

Est. cost: £120-200
Parts: NTC Thermistor, Wiring Harness

Full guide for None

04

c 2 High Engineer

Your boiler has lost its unique configuration settings, meaning it has forgotten how to communicate with its internal control panel.

Est. cost: £150-250
Parts: Boiler Control Connection (BCC) plug, Main Printed Circuit Board (PCB)

Full guide for c 2

05

c 0 High Engineer

Your boiler's computer memory chip is not communicating correctly with the main control board, which prevents the boiler from starting safely.

Est. cost: £150-250
Parts: BCC Plug, Main Control PCB

Full guide for c 0

Parts most often replaced

on the Ideal Independent C24

Central heating pumpFlow sensorNTC thermistorBoiler Control Card (BCC)Wiring HarnessNTC Thermistor

Based on parts cited in our fault code database. Your engineer will confirm what's actually needed after diagnosis.

Call a Gas Safe engineer if…

You can smell gas or see signs of a leak
The Ideal shows an Emergency or High severity code
The boiler keeps locking out after repeated resets
You've tried the DIY checks and the fault hasn't cleared
There's visible water leaking from the boiler
The flame is yellow or orange instead of blue

See the full 5-code list for the Ideal Independent C24