Error F.67

Safety precautions

- If you smell gas, leave the building immediately and call the gas emergency number — do not attempt any checks.

- Turn the boiler off and isolate electrical power at the boiler isolator before removing any covers. If you are not comfortable working near live electrical parts, do not open the boiler.

- Do not attempt to adjust or repair gas valves, burner settings, or any sealed gas components yourself. Only a Gas Safe engineer should work on gas-carrying parts.

- Limit soft resets to a couple of attempts. Repeated resets can mask an ongoing unsafe fault.

Initial homeowner checks (safe, do-first items)

1. Record the exact error code, any other codes, and the time displayed. Take a clear photo of the display and write down any sequence of events (e.g., fault appeared after a power cut, after servicing, or while running hot water).

2. Soft reset: switch the boiler off at the front control and at the isolator or fuse for 30–60 seconds, then restore power and check whether the F.67 returns. Do this no more than twice.

3. Check gas supply: confirm other gas appliances (hob, cooker) work. Check the gas meter and any external isolation valve for being on. If gas supply is interrupted, contact your gas supplier.

4. Check boiler pressure: ensure system pressure is in the normal range (typically around 1–1.5 bar when cold for many systems). If the pressure is very low, follow the manufacturer’s instructions to repressurise (only if you know how). Low pressure can cause ignition problems in some cases.

5. Check the flue terminal and immediate area for obvious blockages (birds, debris) and the condensate pipe if exposed outside for freezing or blockage. While F.67 is electronic, a blocked flue or frozen condensate can cause other ignition faults and should be obvious to inspect.

6. Check the electrical supply: ensure the boiler’s isolation switch and any fused spur haven’t tripped and that the household supply is stable. A brown-out or lost neutral can cause electronic faults.

Specific diagnostic steps you can try if you are competent and willing (power isolated, basic electrical safety observed)

1. Visual inspection: with the boiler isolated from power and gas, remove the outer cover per the manual. Look for obvious signs of damage on the PCB and wiring looms — burnt components, discoloured or melted connectors, loose plug connections, or corroded terminals.

2. Re-seat connectors: with power off, carefully unplug and re-seat the main wiring looms and connectors to the PCB and to the ignition/electrode assembly, then replace the cover and power up to test. Poor connections often cause intermittent flame signal faults.

3. Inspect the ignition/flame electrode and lead: if accessible, check the electrode for heavy carbon build-up, cracking or damage and check the ignition lead for splits or brittle insulation. Light cleaning of a sooted electrode with a dry cloth or very fine abrasive may help if contamination is visible. Do not bend or significantly reposition the electrode unless following the service manual. Re-seat and check again.

4. Earth/ground check: a poor earth connection can stop a flame signal being read. Visually check the earth connection to the boiler cabinet and any earth wires for looseness or corrosion. Tighten only with power isolated.

5. Basic multimeter checks (only if experienced): measure continuity of ignition lead and look for obvious short circuits on visible wiring. Do not attempt high-voltage or live-current measurements unless qualified. Many flame-sensing faults require specialist test equipment and knowledge of Vaillant service parameters.

When to stop and call a professional

- If the fault returns after the basic checks and reseating connectors, or if you find burnt components, damaged wiring, or persistent errors: stop and call a Gas Safe registered engineer. F.67 commonly points to PCB/flame circuit failure or a faulty electrode/ignition component that requires accredited replacement and commissioning.

- If you are unsure about any step, or if any gas-side components or the PCB need replacing, book a Gas Safe engineer. Tell them the model (Vaillant Turbomax Plus 824/828E), give the exact error code F.67, say what checks you have already done, and send the photo(s) you took.

Other practical advice

- Do not repeatedly reset the boiler in an attempt to clear the fault; if it reoccurs, leave the boiler off and seek professional help.

- Take photos of connectors, wiring, and the fault display to help the engineer diagnose more quickly.

- A qualified engineer will perform safe gas and electrical diagnostics, check flame signal voltages, test/replace the ionisation electrode or ignition lead if faulty, and if required replace or repair the PCB and then commission the boiler to Vaillant specifications.

Remember: F.67 is primarily an electronic flame detection fault. Homeowner checks can identify simple causes (loose connector, dirty electrode, no gas), but repair and replacement of ignition/flame circuitry or PCB components must be carried out by a Gas Safe registered engineer for safety and legal compliance.