Vaillant Boiler F67 Fault Code
The Vaillant fault code F67 boiler flame failure signal to PCB Q & A or require an engineer for an emergency boiler repair.
The Vaillant Boiler Fault Code F67 Error Common Q&A
Vaillant Boiler F67 Fault Code
- What does the F67 fault code mean on my Vaillant boiler?
- What causes the F67 fault code to display on my boiler?
- How does this differ from an F65 fault?
- Can I fix the problem on a DIY basis?
- What causes loose and damaged connections on a PCB?
- Will an engineer fix loose or damaged connections, or replace the PCB?
- How will the engineer know if a damaged PCB is causing the F67 fault?
- If the circuit board is burnt out or cracked, can it be fixed?
- Why would the PCB or connections on it, burn out?
- Is there a way for me to know if the circuit board is faulty, before the engineer arrives?
- How can the mains input voltage cause an F67 fault code to be displayed on my boiler?
- Can overvoltage damage my boiler?
- Will I need a new boiler if I have overvoltage, or a faulty PCB?
What does the F67 fault code mean on my Vaillant boiler
According to Vaillant, the F67 fault code relates a signal fault on the main PCB.
The boiler isn’t getting the correct flame signal.
What causes the F67 fault code to display on my boiler?
The causes of the flame signal fault could be due to:
- Connections on the PCB (printed circuit board) are loose, or have been damaged
- The PCB has been damaged, and isn’t giving or receiving the correct signals
- The input voltage on the mains electricity is incorrect
How does this differ from an F65 fault?
The F65 fault on a Vaillant boiler will stem from similar problems (for instance, the main input voltage is incorrect).
However, in the case of the F65 fault, the boiler recognises a PCB that is operating above its working temperature, and is likely to fail.
This differs to the F67 fault whereby the boiler recognises the flame signal is non-existent, weak, or intermittent.
Can I fix the problem on a DIY basis?
Many homeowners try resetting their boiler to clear the F67 fault. This may clear the fault, but only for a brief period of time.
As soon as the boiler recognises the fault still exists, it will display the F67 fault again.
Always speak to a Gas Safe registered engineer. To fix this problem, they will need to remove the boiler casing, and start dismantling your boiler.
This is classed as working on a gas appliance, and the job should only be completed by a qualified engineer.
Once the job is complete, they will reset your boiler.
What causes loose and damaged connections on a PCB
Circuit boards are notoriously fragile. Connections can work loose over years. This is helped along thanks to the vibrations from internal boiler components (such as the pump and fan).
But, damaged connections are a different thing altogether. Typically, damaged connections and soldered joints come from water damage.
It’s a time-consuming process to repair them. And, with the cost of labour it’s sometimes worth considering a PCB, or a new boiler.
Will an engineer fix loose or damaged connections, or replace the PCB
First, the engineer needs to diagnose the fault. Loose and damaged connections are easily spotted with a simple visual check.
However, that doesn’t mean that’s the only fault. After rectifying problems with loose and damaged electrical connections on the PCB, they’ll need to test the PCB itself.
If there’s an internal fault with the PCB, it’s much more likely that they’ll suggest replacing the circuit board, rather than trying to repair it.
How will the engineer know if a damaged PCB is causing the F67 fault
Besides loose and damaged connections, there are some tell-tale signs of a faulty boiler PCB.
A typical example would be soldered joints that are completely burnt out.
Or on some occasions, small hairline fractures in the board itself.
When cracks pass through parts of the PCB that provide signals, it can cause faults, and that in turn can cause the F67 fault code to be displayed.
If the circuit board is burnt out or cracked, can it be fixed
It’s only rare instances where it’s worth fixing a PCB. Not just because of the time spent on labour, either.
PCBs are expensive items, and so is repairing them.
The last thing you want to do is invest lots of cash into an electrical unit (especially if it’s 5+ years old and outside of manufacturer’s warranty), only for it to fail completely a few months down the line.
Why would the PCB or connections on it, burn out
Years of strain can cause failures; it’s general wear and tear.
However, a common reason parts of the PCB burn out, comes from leaking boilers. Just the slightest hint of water (or condensation) on the PCB, can cause small power surges that burn out connections.
If you’ve noticed small pools of water beneath your boiler, get your engineer to diagnose and fix the leak.
Otherwise, once the electronic issue has been fixed, it’s likely to happen again in the future.
Is there a way for me to know if the circuit board is faulty, before the engineer arrives
A PCB controls all electronic components in your boiler. It sends and receives various signals throughout the start-up, operational and shut-down sequence.
When connections are loose or broken, it will receive and send out the wrong, intermittent or no signals at all.
hat’s going to make your boiler work intermittently.
So, it might cycle on and off for no apparent reason. Or, it might not heat up radiators to full temperature.
Essentially, it will work sporadically.
How can the mains input voltage cause an F67 fault code to be displayed on my boiler
This can get incredibly complicated. There’s a fine line between diagnosing an intermittent and faulty PCB, bad connections and a problem with input voltage.
But, if you do have an overvoltage problem, it’s likely that other (less robust) appliances are feeling the force of it, not just your boiler.
If your appliances are blowing fuses, or regularly tripping the RCD in your property, this could be a sign of overvoltage.
However, you’ll need to get a gas engineer with electrical testing equipment to test if this is the case.
If it’s an actual supply issue, you’ll then have to contact your utility provider to rectify the problem.
Can overvoltage damage my boiler
This is one of the reasons we suggest not trying to reset a boiler to clear fault codes. Overvoltage (depending at what level), can damage your boiler.
Your boiler displays all kinds of fault codes, depending on the fault.
It will then lockout (cease to operate, until the problem is fixed, and the boiler is reset).
This lockout is a safeguard for:
- You, in case the boiler is dangerous (for example, it’s leaking gas)
- The boiler’s parts (they risk getting damaged if the boiler continues to operate)
In the case of overvoltage, all electronic components are at risk. And included in the list of parts, is your PCB.
So, even if an overvoltage problem is identified and fixed, it may have already caused issues with not just your PCB, but other electronic components too.
Will I need a new boiler if I have overvoltage, or a faulty PCB
There are various electrical tests that can be completed to determine the state of electronic components. This is the first step to determining if the boiler is worth fixing, or replacing.
If parts including the PCB have been fried by a surge in electrical current, it might be worth considering a replacement boiler.
However, if minor repairs can be made to rectify the electrical issues, your boiler could last for years to come.
But, it’s not just electrical components that need to be assessed. Boilers have a range of expensive parts such as heat exchangers, fans, pumps and gas valves.
With most mechanical appliances (not just boilers), once one part degrades, others tend to follow.
So, it’s wise to have a gas engineer check over not just electrical components, but other important ones too.
This will give a clear picture of whether the boiler is worth repairing, or replacing.
Other Vaillant Fault Codes And Error
If your looking for the list of error codes relating to the Vaillant boiler then please read the article Vaillant Boiler Fault Codes And Cures