Error code
Vaillant Boiler Fault Code F67
Quick answer
F67
Control board or internal communication fault
First safe action
Try one standard user reset if the manual permits it.
Meaning
Vaillant boiler fault code F67 usually means the boiler has detected an internal electronics or communication problem.
Likely causes
- Control board issue
- Loose or damaged internal wiring
- A connected component failing to respond correctly
Safe first checks
- Try one standard user reset if the manual permits it.
- Do not keep resetting if the fault returns straight away.
- Arrange professional diagnosis for persistent control faults.
How to reset
- Use the normal user reset once only.
- Book an engineer if the boiler remains locked out.
When to call an engineer
Persistent electronics and communication faults need a qualified heating engineer rather than further user troubleshooting.
Safety warning
Do not remove the casing or attempt internal electrical repairs on the boiler.
Useful hub links
Related fault codes
F64 for Vaillant Boiler
A boiler sensor is giving an invalid reading
F65 for Vaillant Boiler
The boiler has overheated or hit a high temperature limit
F72 for Vaillant Boiler
A boiler sensor is giving an invalid reading
F75 for Vaillant Boiler
Water circulation or pump performance issue
F62 for Vaillant Boiler
Gas supply control or gas valve issue
F76 for Vaillant Boiler
The boiler has overheated or hit a high temperature limit
Relevant guides
Frequently asked questions
Can I keep resetting a Vaillant boiler with F67?+
No. If F67 returns after one standard user reset, stop there and arrange a qualified engineer if the manual gives no safe next step.
Is F67 something I can repair myself?+
Boiler faults should be treated cautiously. Stay within the user checks in the manual, and leave gas, combustion, and internal boiler repairs to a qualified professional.