Brr! It’s a proper chilly morning, and just when you’re ready for a hot cuppa and a warm shower, your Vaillant boiler flashes the F61 fault code. No heating, no hot water, and a whole lot of “oh no!”
Don’t fret - here at Heatable, we’re all about making boiler woes disappear faster than a biscuit at tea time.
In this guide, we’ll explain what the Vaillant F61 fault code is, why it’s happening, and how to get your home toasty again.
Let’s jump in!
Key takeaways:
F61 Error Code: Indicates a gas valve or communication issue where the boiler’s PCB can’t control the gas valve properly.
Common Causes: Possible issues include a faulty gas valve, wiring problems, a failed PCB, or gas supply issues.
Basic Troubleshooting: Check the gas supply, reset the boiler, and ensure there’s no obvious issue like a gas leak.
When to Call a Professional: If the problem persists after basic checks, contact a Gas Safe engineer for further inspection and repair.
In many cases, upgrading your old boiler to a new, more efficient model is the best solution.
Get a New Quote (Finance Available, Including 0% APR).
What Does the Vaillant F61 Fault Code Mean?
The F61 fault code on your Vaillant boiler is a red flag that something’s amiss with the gas valve or its connection to the boiler’s brain - the printed circuit board (PCB).
According to Vaillant’s ecoTEC manual, it’s a “fuel valve actuation fault,” meaning the PCB can’t properly communicate with the gas valve, which controls gas flow to the burner. As a safety measure, the boiler locks out, leaving you without heat or hot water.
This is a gas-related issue, so it’s not one to ignore. But don’t worry - we’ll break down the causes and what to do next.
Can You Fix the Vaillant F61 Fault Yourself?
Let’s be clear: the F61 fault is not a DIY job. It involves gas and complex electronics, so only a Gas Safe registered engineer should touch it. Fiddling with gas components yourself is dangerous and illegal under UK Gas Safety Regulations.
That said, there are a couple of safe steps you can try before calling for help:
Reset the Boiler: Press and hold the reset button (often a flame with a cross) for up to 10 seconds. This might clear the fault for a bit, but if F61 comes back, stop resetting - it could mask a serious issue.
Check the Gas Supply: Make sure your gas meter has credit (if prepaid) and the gas valve to the boiler is open. If you smell gas, leave your home immediately and call the National Gas Emergency Service on 0800 111 999.
If these don’t work, it’s time to call in the pros. Don’t delay - this fault needs expert attention.
Common Reasons Why This Error Code Appears
When diagnosing the cause of the F61 fault code on your boiler, a registered Gas Safe engineer will likely inspect the following components:
Gas Supply Issue
One of the less common - but still possible - causes of an F61 error code is a gas supply fault, i.e. no gas supply to your boiler
It’s the boiler equivalent of trying to start a car with an empty petrol tank - nothing’s going to happen!
You can check if this is the issue by testing other gas appliances in your home, like your cooker or fire. If they’re not working either, you’ve likely got a gas supply problem.
This could be due to your energy company cutting off the supply, gas works in your area, or simply forgetting to top up your meter (if you have a prepaid one).
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Cost to fix: £50–£100
Faulty Gas Valve
A faulty gas valve is one of the most common culprits behind the F61 error.
Image showing a standard gas valve
The gas valve’s job is to control the flow of gas into the boiler. If it’s not working, no gas reaches the burner, and your boiler can’t heat your water. The fault could be mechanical (the valve is stuck) or electrical (a wiring issue).
Unfortunately, we can’t help with Aunt Marge’s dodgy gas valve after a Sunday roast - just keep her away from the beans!
Cost to fix: £200–£320
Wiring Fault
The gas valve and PCB are connected by a wiring harness, and if there’s a problem here, communication breaks down.
Image showing standard wiring
Think of the PCB as your boiler’s brain and the wiring as its nervous system. A loose or damaged wire is like a bad phone line - messages don’t get through, and the gas valve doesn’t know what to do, causing the boiler to shut off.
Cost to fix: £100–£500
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Mechanical Fault
Sometimes, the gas valve itself has a mechanical issue. Over time, wear and tear can cause the valve to stick, meaning it can’t open or close properly to let gas through.
Image showing a standard gas valve
A sticky gas valve is like a rusty gate - it just won’t budge when you need it to. This stops the gas flow, and your boiler locks out, displaying the F61 code.
Cost to fix: £150–£300
PS: You may be interested in Gas Engineer Allen Hart explaining the most common boiler problems and how you can resolve them in the video below:
PCB Fault
The printed circuit board (PCB) is the control centre of your boiler, managing all its components, including the gas valve.
Image showing a standard PCB
If the PCB is faulty, due to a short circuit or component failure, it can’t send the right signals to the gas valve. It’s like trying to run a team with a manager who’s lost their voice - nothing gets done, and the boiler shuts down.
For Father’s Day, how about a card that says, “Dad, you’re the PCB of our family”? We’ll take the credit for that one.
Cost to fix: £360–£500
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How a Gas Safe Engineer Will Fix the F61 Fault
A Gas Safe engineer will follow a step-by-step process to diagnose and fix the F61 fault. Here’s what they’ll likely do:
Inspect the Gas Valve: They’ll check if the valve is stuck or broken. A seized valve might be freed, but a faulty one will need replacing, costing around £200–£320.
Check the Wiring: The engineer will look for loose, damaged, or corroded connections. Minor wiring fixes are quick, but a new harness might be needed.
Test the PCB: If the valve and wiring are fine, the PCB could be the culprit. A faulty PCB can cost up to £500 to replace, and for older boilers, a new unit might be a better bet.
Verify Gas Supply: They’ll ensure gas pressure is adequate and there are no blockages.
Full Boiler Check: A good engineer will inspect other parts, like the pump or sensors, to catch any issues that could cause future faults.
Repair costs depend on the problem. Labour typically runs £30–£60 per hour, plus parts. A gas valve might set you back £200–£320, while a PCB could be £360–£500. If parts need ordering, you might be without heat for a day or two.
Costs to Fix the Vaillant F61 Fault Code
Here’s a quick breakdown of potential repair costs for the F61 fault, based on the issue:
Gas Supply Issue: £50–£100 (if it’s a simple fix like topping up your meter or resolving a supply issue).
Faulty Gas Valve: £200–£320 (includes parts and labour for replacement).
Wiring Fault: £100–£500 (depends on the extent of the damage and whether a full harness replacement is needed).
Mechanical Fault in Gas Valve: £150–£300 (if the valve needs freeing or replacing due to wear).
PCB Fault: £360–£500 (PCBs are expensive, and labour can add up).
Labour typically costs £30–£60 per hour, and if parts need ordering, you might be without heat for a day or two. For older boilers, these costs might make a replacement a better option.
How to Prevent the Vaillant F61 Fault Code
Nobody wants a repeat of the F61 drama. Here’s how to keep your boiler in top shape:
Annual Servicing: A yearly check-up by a Gas Safe engineer can spot issues like worn valves or loose wiring before they cause trouble. It also keeps your warranty valid.
Check for Leaks: Water leaks can damage wiring or components, so keep an eye out for drips around your boiler or pipes.
Ensure Ventilation: Proper airflow prevents overheating, which can stress the PCB and other parts.
Consider a New Boiler: If your boiler’s over 10 years old, a new, efficient model could save you from frequent repairs.
Do You Need A New Boiler?
In some cases, replacing a boiler can make more financial sense than continuing to repair it. Here are the key factors to consider:
Age of the Boiler - If your boiler has surpassed its average lifespan (typically beyond 15 years) and is no longer covered by the manufacturer’s warranty, replacing it may be a more cost-effective option to avoid recurring repair expenses.
Repair Costs - When the cost of repairing the boiler exceeds 50% of the price of a new one, it’s usually more financially sensible to invest in a replacement rather than continuing with costly repairs.
Frequency of Breakdowns - If your boiler is breaking down more frequently, it’s often a sign of significant wear and tear and it is beyond economical repair. In such cases, replacing the boiler can help avoid mounting repair costs and the inconvenience of ongoing issues.
Energy Efficiency - Older boilers tend to be far less efficient than modern models, leading to higher running costs. Upgrading from a G-rated to an A-rated boiler could save you up to £385 per year in energy bills, making replacement a financially smart decision in the long run.
By carefully weighing these factors, you can determine whether replacing your boiler offers better value and peace of mind compared to continued repairs.
Learn all about combi boilers in our what is a combi boiler.
Key Takeaways:
F61 Error Code: Indicates a gas valve or communication issue where the boiler’s PCB can’t control the gas valve properly.
Common Causes: Possible issues include a faulty gas valve, wiring problems, a failed PCB, or gas supply issues.
Basic Troubleshooting: Check the gas supply, reset the boiler, and ensure there’s no obvious issue like a gas leak.
When to Call a Professional: If the problem persists after basic checks, contact a Gas Safe engineer for further inspection and repair.
In many cases, upgrading your old boiler to a new, more efficient model is the best solution.
Get a New Quote (Finance Available, Including 0% APR).
Wrapping Up
The Vaillant F61 fault code is a proper nuisance, but with the right help, it’s fixable. While a quick reset might buy you time, this gas-related issue needs a Gas Safe engineer to sort it properly.
To avoid future chills, keep up with servicing and consider a new boiler if yours is past its prime.
Got an F61 fault or other boiler troubles? Don’t shiver through it - reach out to Heatable. We’ll connect you with expert engineers or a shiny new Vaillant boiler to keep your home cosy.
Disclaimer: Never attempt to fix gas-related boiler faults yourself - it’s dangerous and illegal. Always hire a Gas Safe registered engineer. For more Vaillant fault code tips, visit our Boiler Advice Hub.
Get a Quote for a New Boiler Today
The best way to resolve the F61 error code is to seek the help of a registered Gas Safe Engineer, who will be able to diagnose and repair whatever is causing the F61 code to be displayed.
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