Vaillant Boiler F61 Fault Code Explained [And What To Do Next]

If your boiler has stopped working and it’s showing the F61 fault code on the display panel, this guide is going to help you figure out what the error code means, and what to do next.

What does the F61 error code mean on Vaillant Boilers?

Put simply, the F61 error code relates to a gas valve fault. You’ll need to book in a Gas Safe engineer to find and fix the fault, as they’re the only people that are qualified to work on gas appliances.

Why your boiler stops working when the F61 fault code is displayed

It goes without saying that a boiler with a gas fault is potentially dangerous. Your printed circuit board monitors a range of sensors to determine whether your boiler is working safely and efficiently.

In this case it’s not, so it locks out to be on the safe side.

The cost to replace a boiler gas valve

As we’ll mention below, in some scenarios, gas valves on boilers can be fixed. But, if your Gas Safe engineer thinks there’s even the slightest chance of the fault persisting, a replacement is going to be needed.

The overall cost of a replacement is going to be in the region of £300 (boiler dependent). You can book in a Gas Safe engineer to give you a quote here.

If your engineer assesses your boiler, and other parts (such as the fan, pump and PCB) are on their way out, it might be time to consider a replacement boiler instead of a repair.

You can get great deals on boilers through BOXT by filling out a simple on-screen form; it takes less than 90-seconds.

How gas valve faults develop on your boiler

In most cases, the gas valve has become stuck, or is completely seized. They’re mechanical parts so this is natural over time.

However, in other cases, the problem could be connected to wiring issues, a faulty valve, or even a communication error with the boiler’s main circuit board.

  1. Stuck & seized valves

Stuck and seized valves can sometimes be freed. As we’ve mentioned, you’ll need to book a Gas Safe engineer and they’ll be able to asses the damage. If the valve can’t be completely freed, it’s likely they’ll suggest a replacement.

If the valve is partially stuck open, it could be letting gas into the combustion chamber when it shouldn’t; this is potentially dangerous. And when it’s working on the flip side (stuck partially closed), it’s starving your boiler of gas.

  1. Problems with wiring and connections

Another common reason the F61 fault code is displayed, is due to faults with wiring and connections.

Wiring can easily come loose because boiler parts such as the pump and fan, vibrate. Likewise, connections can be come damaged, sometimes due to old age, or on other occasions because of further problems with your boiler, such as leaks causing water damage.

Small issues with wiring and connections can be fixed and secured. But if in doubt, your Gas Safe engineer will simply replace the valve (sometimes this is less than the cost of labour for a repair).

You can book a boiler repair engineer to check your gas valve here.

  1. Faulty gas valve

Not all gas valves can be fixed. Sometimes, the combination of wear and damage means that the valve isn’t cost effective to fix.

Your boiler engineer will be able to test the valve and determine if this is the case. If so, unfortunately a replacement is going to be needed.

  1. Printed circuit board fault

We’ve seen instances where the F61 fault is nothing to do with the gas valve, even though that is the stated cause.

If your engineer is confident the valve isn’t the problem, it’s likely to be a problem with the wiring harness that connects the gas valve to the PCB.

The PCB is the control hub for your boiler, and all electronic parts rely on it for signals, so they know exactly when to operate (and when to cease operation). If there’s a problem here, it’s simply going to lockout.

Unfortunately, the cost of a PCB replacement can sometimes be as much as £500 (although you can get a quick quote here to check).

If your boiler is out of warranty and needing repairs of this magnitude, in general, it makes sense to consider a replacement.

You can get on-screen prices for a replacement boiler here, in less than 90-seconds.

What’s Next?

Still got problems with your Vaillant Boiler showing the F61 fault code? Or, is it showing more than one fault code and your engineer can’t find the problem?

Check out our guide to other Vaillant Boiler problems, or drop us a line via our contact form, and we’ll do our best to help you out.