Common problems guide

The most common Ideal i Mini problems

The faults most likely to send a Ideal i Mini 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.
3 documented codes
3 most common
0 DIY-safe checks
3 engineer needed

The 3 most common faults

01
c2 High Engineer

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

Est. cost
£150-300
Parts
Boiler Chip Card (BCC), Main PCB
Full guide for c2
02
L1 High Engineer

Your boiler has detected that the water inside the system has become dangerously hot and has shut itself down to prevent damage or overheating.

Est. cost
£150-300
Parts
NTC Thermistor, Primary Heat Exchanger, Pump
Full guide for L1
03
c0 Medium Engineer

Your boiler is struggling because the electricity supply feeding it has dropped below the minimum voltage required to function safely.

Est. cost
£100-250
Parts
Printed Circuit Board (PCB), Wiring harness
Full guide for c0
Parts most often replaced

on the Ideal i Mini

Boiler Chip Card (BCC)Main PCBNTC ThermistorPrimary Heat ExchangerPumpPrinted Circuit Board (PCB)

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 3-code list for the Ideal i Mini

Related guides

Boiler losing pressure → No hot water → When to replace → Symptom checker →