Vaillant F61 Fault Code Explained
Hertfordshire, Bedfordshire & Cambridgeshire
An F61 fault on a Vaillant boiler points to a control electronics fault. Vaillant records it as the ASIC or microcontroller on the circuit board not running within its defined timings, which affects the board ability to control the gas valve safely.
Like F62, this is gas valve territory and needs a Gas Safe engineer.
What F61 actually means
The circuit board drives the gas valve and monitors that it is responding correctly. If the board own control timing falls outside tolerance, it cannot guarantee safe control of the valve, so it shuts the appliance down. That is why this is a board fault that presents as a gas valve code.
What you can safely check yourself
Nothing on this one. There is no homeowner check that helps with F61, and the components involved are inside the appliance. This needs a Gas Safe engineer.
When to stop, and why
What causes it beyond the simple checks
Most often the PCB itself. Also a wiring or connector fault between the board and the valve, or a failed gas valve coil. On older appliances the economics of a board replacement are worth discussing against replacing the boiler.
How Vantage can help
We are Gas Safe registered and cover Hertfordshire, Bedfordshire and Cambridgeshire, with an emergency line answered 24 hours a day.
Call us on 01462 506374. See also boiler repair and Vaillant boiler installation.
Frequently asked questions
Is F61 the board or the valve?
Vaillant own wording points at the control electronics rather than the valve. It can still be the wiring or the valve coil, so it needs testing rather than assuming.
Is it worth repairing?
On a newer boiler, usually. On an old one, get the arithmetic before committing.
Can I reset it?
It will not help, and gas valve faults should not be repeatedly reset.
Related fault codes
Other Vaillant codes: Vaillant F22 · Vaillant F75 · Vaillant F28 · Vaillant F29 · Vaillant F27 · Vaillant F20 · Vaillant F23 · Vaillant F83 · Vaillant F32 · Vaillant F62 · Vaillant F72
See also our guide to boiler not firing up, the full boiler advice section, and boiler repair.
In Vaillant’s own words
Vaillant describes F61 as the ASIC or microcontroller not running in the defined times.
That places F61 on the control board rather than at the gas valve, which is where a lot of general advice wrongly sends it. Worth knowing before anyone quotes you for a valve.
When to call an engineer
If the fault keeps returning after a reset, it is telling you something is degrading rather than broken. Call 01462 506374 and we will diagnose it properly rather than swapping parts and hoping. Gas Safe registered 956889, 12 months on our own labour.
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