Ideal C2 fault codewhat it means and how to fix it
The Boiler Chip Card in the control board is wrong for this boiler, missing from an unprogrammed board, or has failed. Ideal's sequence ends with a new card, then a new PCB.
Take care
Get a Gas Safe registered engineer to look at your Ideal C2
We do not pass enquiries to a repair firm, so there is no form here. Find a Gas Safe registered engineer through the Gas Safe Register, and ask to see their registration card when they arrive — it is the register, not the van, that tells you they are qualified.
What C2 means
C2 is BCC Fault. Where C0 is the board failing to wake the card up, C2 is the board having read it and rejected it. Ideal's i combi manual gives two routes to the code.
One is procedural: fit a new primary PCB without a card and, in their words, "if no BCC fitted on non programmed board C2 will be displayed" — the correct BCC for the appliance then needs to be fitted. The other is the card itself: the engineer frame asks whether the correct card for the boiler, identified by the label on it, is securely inserted TOP side up in the slot at the front left of the PCB; if not, insert it, power on, wait for c0 to show and reset; if it was already correct, replace the card with a new one for the boiler and repeat; if c2 is still shown, replace the PCB.
The 2011 Logic+ called the same condition PCB Replacement on its screen, with the action Reset Boiler. The householder version, as for every code in this table, is reset once and then contact Ideal or a Gas Safe engineer.
What causes it
| Cause | What is actually happening | How likely |
|---|---|---|
| Wrong card for the model | The cards are output-specific — 24, 30 or 35 kW — and a card from a different Logic will be rejected. Ideal's frame asks for the label to be checked before anything else. | Common |
| New PCB fitted with no card at all | Ideal state this produces C2 directly. The board is fine and unprogrammed; it needs its card. | Common |
| Card failed | The chip card is a small EEPROM and does occasionally die. The test is a new card for the same boiler; if that clears it, the old one had gone. | Occasional |
| PCB slot or reader fault | A correct, new, correctly seated card still showing C2 leaves the board itself, which is where Ideal's frame ends. | Rare |
Can you fix it yourself?
Stop — this needs an engineer
What it costs to fix
Typical repair cost
£60–£380
Time on site
30 minutes
Fitting the correct card £60–£120 including the part. A PCB and card together £250–£380 fitted.
Typical UK prices including parts and labour, updated September 2026. Your quote may differ.
Parts you may need
We may earn a commission if you buy a part through one of these links. It does not change what you pay, and it does not affect which parts we list.
Ideal Logic primary PCB
£150–£320Authorised Ideal parts distributor
Price checked 28 September 2026
Own this appliance and had this code? . Nothing is published until a person has read it.
Related Ideal fault codes
- F9Get it checkedThe control board has not been told what boiler it is in, or has failed. L9 is the same fault locked out. The 2011 Logic Combi row also covers a gas valve short circuit.Related: electronics and power
- dUUsually simple to fixNot a fault. The diverter valve has been parked in its mid-position for servicing and the boiler is waiting to be told the service is over. Ideal publish the way out.Related: electronics and power
- Blank displayGet it checkedNothing on the screen at all. Ideal's user guides send you to the boiler's switch and the consumer unit first; the installer charts then work from the terminal block to the board.Related: electronics and power
- F7Get it checkedThe mains voltage reaching the boiler has dropped below what the board will run on. Ideal's advice is an electrician or your electricity supplier, not a heating engineer.Related: electronics and power
- C0Get it checkedThe board cannot activate the Boiler Chip Card that tells it what model it is fitted to. Ideal's engineer check is whether the small plastic card is in its slot at all.Related: electronics and power
- L9Get it checkedOn a Logic, L9 is the locked-out form of the unconfigured-board fault F9. On an Isar HE it is something else entirely: a heat exchanger overheat read by the dry-fire thermistor.Related: electronics and power
Own an Ideal boiler? Save it and its codes come first next time.
Related guides
Common questions about Ideal C2
Is C2 the same as C0?
Related but not the same. C0 is an activation failure — usually no card present. C2 is a card that is present and wrong, or a board that has been replaced and not yet given one. Ideal's engineer frames are separate and C2's is the longer.
The boiler showed c0 and then c2 after a repair. What happened?
That is Ideal's documented sequence when a card is inserted into a fresh board: power on, c0 appears, reset. If c2 follows, the card was not the right one for this appliance or was not seated. Ring whoever did the repair.
Why does the card matter so much?
Because it tells the board the burner size, and the board uses that to set fan speed and gas rate. A board running a 35 kW programme on a 24 kW burner is a combustion problem, not a display problem, which is why the fix is restricted to Gas Safe engineers.
Technical review
Not reviewed by an engineer
No engineer has read this page. Severity follows what the manufacturer publishes, and we would rather tell you that than let a byline imply a sign-off.
Sources and how we verified this
We establish the facts from the sources below and then write the explanation ourselves. We do not copy manufacturer wording and we do not host their manuals.
- Manufacturer technical and service documentation
- Manufacturer support portal
This page has not been reviewed by an engineer, and we would rather tell you that than imply otherwise. The severity rating follows what the manufacturer publishes: where they say isolate the appliance and call someone, so do we.