Error C0

Safety precautions:

1. Before touching the boiler, turn off the electrical supply at the boiler isolator or fuse spur. If you are unsure where this is, switch off the consumer unit (fuse box) circuit to the boiler. Do not work on the boiler with the power on.

2. Do not attempt to access or replace gas-carrying components, the main PCB or any sealed parts unless you are a Gas Safe registered engineer. Electrical components and PCBs can retain charge — if in doubt, call a professional.

3. If the boiler is under warranty, contact Ideal or the installer before attempting anything that might affect warranty cover.

Initial homeowner checks you can safely do:

1. Note any other codes or display messages and whether heating/hot water are working at all. Write down exact display text and behaviour.

2. Try a normal reset first: use the reset button or hold the mode dial in the reset position for 3 seconds (check your model user guide for the correct reset method). Wait a few minutes for the boiler to attempt restart and see if the C0 clears.

3. Power-cycle the boiler: switch off at the boiler isolator/fuse spur and leave off for 30–60 seconds, then restore power and check the display again.

4. Check for recent work: ask whether the PCB or any control parts were recently replaced or the boiler serviced. A newly fitted or incorrect chip card following PCB replacement is a common cause.

If the code persists — safe visual checks you can perform with power off:

1. Isolate electrical supply to the boiler. Remove the front cover only if you are comfortable and the manual shows how; otherwise skip to calling a professional.

2. Locate the Boiler Chip Card (refer to the manual for its position). Carefully remove it and inspect for obvious damage, corrosion, bent contacts or dirt. If contacts are dirty, only with power off you may gently blow out dust or use a dry, soft brush — do not use liquids.

3. Re-seat the card firmly in its slot ensuring it sits correctly. Replace the cover, restore power and attempt a reset/power-cycle again.

4. If you have documentation showing the correct chip card part number (for example after a PCB change), confirm the installed card matches the correct part. Do not attempt to swap cards from other appliances or use third-party replacements without guidance from Ideal or an installer.

When to call a professional:

1. If the C0 code does not clear after resets, power-cycling and reseating the chip card, stop and contact a Gas Safe registered heating engineer or Ideal Technical Support. Persistent C0 usually requires special fault diagnostics, reprogramming or replacement of the chip card or PCB and must be handled by a trained engineer.

2. If you see any other fault codes appearing, loss of display, burning smells, visible damage to the PCB, or if the boiler behaves erratically (e.g. intermittent operation), isolate the boiler power and call a professional immediately.

3. If the installer recently worked on the boiler (for example replaced the PCB), contact them first as the issue may be related to an incorrect or unprogrammed chip card and they may resolve it under service terms or warranty.

Final notes:

Do not attempt gas or PCB repairs yourself. The BCC/PCB system is a control-level, manufacturer-specific component and resolving C0 typically needs diagnostic tools, replacement parts or reconfiguration only available to qualified engineers or the manufacturer. Keep records of the fault code, any actions you took, and the boiler serial/model when you contact support or an engineer.