Error F0 262

Safety precautions:

1) If you smell gas or see signs of burning or smoke, leave the building immediately and call the gas emergency number. Do not attempt any checks.

2) Before touching any internal components, switch the boiler off at the mains isolator and isolate any external electrical supplies. Do not work on gas or live mains unless you are a Gas Safe qualified engineer.

3) Work only on visual, external checks if you are a homeowner. Do not attempt to remove, replace or solder electrical components or the HCM/control PCB.

Initial checks a homeowner can do:

1) Record the full display exactly as shown including the F0 262, any flashing triangle (locking error) and any three‑digit cause code that appears when you press the spanner/return button. This information is what the engineer will need.

2) Try a normal reset first: press and hold the reset/✔ button for about 8 seconds until the boiler reboots. Note whether the fault returns immediately or after a short run.

3) Power‑cycle the boiler: switch off at the mains isolator, wait 30 seconds, then switch on and observe the fault display. This can clear temporary internal errors.

4) Check the boiler’s service history and warranty—if under warranty, contact Worcester Bosch or the installer before further intervention.

Specific diagnostic checks you may safely perform (visual, non-invasive):

1) With the boiler isolated from mains power, remove the outer cover only if you are comfortable and it is straightforward to do so without disturbing sealed pipework. If in doubt, stop and wait for the engineer.

2) Visually inspect connectors and wiring around the control box and HCM for loose plugs, disconnected cables, signs of water/condensate ingress, corrosion, charring, or broken pins. Do not attempt to power the boiler with exposed wiring.

3) Check the code plug / identification plug (if fitted) is present and seated correctly – a missing or loose code plug can cause control/HCM communication errors.

4) Check ignition leads and electrode connections are dry and appear intact; inspect for melted or burned insulation. Do not attempt to clean electrodes or adjust gas components unless qualified.

5) Ensure there is no obvious condensate leak or water pooling inside the case that could have reached the PCB/HCM – water damage commonly causes control faults.

6) If you find a clearly loose multi‑pin connector and you are competent with safe isolation, isolate the mains, carefully unplug and reseat the connector, then power back up and observe whether the code clears.

What to do next and when to call a professional:

1) If the reset and reseating connectors (if you performed that) clear the error and the boiler runs normally for a sustained period, monitor it and book a service to have the control box/HCM checked professionally.

2) If the fault returns, the display remains F0 262, or you see related codes (9U, C4, F0 with other cause numbers, 9A indicating incorrect HCM), stop further DIY. These point to an internal electronic fault, incompatible or failed HCM, damaged control PCB, or a faulty code plug and require replacement or specialist diagnostics.

3) Contact a Gas Safe registered engineer or Worcester Bosch technical support. Provide them with: exact fault code (F0 262), any flashing triangle or cause code seen after pressing the spanner/return, what you tried (reset, power cycle, reseated connectors), boiler model and serial, and last service date. If the boiler is under warranty, tell them that immediately.

4) Do not attempt to replace the control box or HCM yourself unless you are Gas Safe and competent with boiler electronics; replacement involves checks, commissioning and safe re‑connection of gas and sensors.

Additional notes:

1) Some similar F0 variants relate to ignition leads or connector contacts, so the visible issue can sometimes be a loose lead rather than a full PCB failure. However persistent or recurring F0 262 should be handled by a professional.

2) Keep the boiler powered off if there are obvious signs of water damage or burning until an engineer has inspected it. Document any symptoms and take photos of the error display to speed up diagnosis when the engineer arrives.