Glow-Worm Boiler F4 Fault Code
The Glow-Worm fault code F4 relates to the ignition fault and here we have Q & A or require an engineer for an emergency boiler repair.
The Glow-Worm Boiler Fault Code F4 Error Common Q & A
Just below, we have a list of common questions relating to the F4 fault code on the Glow-Worm Boiler.
- What does the F4 fault code mean on my Glow-Worm boiler?
- Can I reset my boiler to fix the F4 fault?
- What could cause the F4 ignition fault on my Glow-Worm boiler?
- How will my boiler engineer determine the problem?
- What could be wrong with the flue that causes the F4 fault code to be displayed?
- How does gas pressure affect my boiler’s ability to operate?
- My boiler engineer thinks the problem is with the gas valve, could this be right?
- I need a new gas valve on my boiler, how much is it going to costI need a new gas valve on my boiler, how much is it going to cost?
- What happens if the burner on my Glow-Worm boiler is blocked?
- Which electrical parts need to be inspected, that help a boiler to ignite?
- What else does my boiler engineer need to check to clear the F4 fault code?
- How do I know if I need a new boiler?
What does the F4 fault code mean on my Glow-Worm boiler
If your Glow-Worm boiler is showing the F4 fault code on the display panel, it means there is an ignition fault.
It’s the printed circuit board (PCB) on your boiler that controls electrical components. It receives signals from a range of sensors to determine that components are operational when they should be, and that the boiler is working within tolerances. When it’s not it will lock out and display a fault code.
Can I reset my boiler to fix the F4 fault
Resetting your boiler isn’t a way to fix a fault. Instead, it’s designed to be used when the problem has been found and fixed.
After a fault code is displayed, your boiler should lock out. In the case of the F4 fault code, the issue could relate to anything from harmful flue gases not escaping via the flue, to the incorrect level of gas being supplied to the burner. If the boiler was to continue to operate, it could be dangerous.
For that reason, you should leave resetting your boiler to a Gas Safe registered repair company. They’ll find and fix the fault, and then reset your boiler on your behalf.
What could cause the F4 ignition fault on my Glow-Worm boiler
Fault codes do help boiler repair engineers find the faulty quicker than if they had to test every component. However, there are still a lot of potential culprits that they’ll need to work their way through. In the case of the F4 ignition fault, the problem could lie with the:
- Inlet gas pressure
- Gas valve being incorrectly adjusted, sticking, or simply being faulty
- Burner being blocked
- Flue or condensate pipe being blocked
- Spark generator, ignition lead or probe being faulty
How will my boiler engineer determine the problem
If it’s freezing cold, a good place to start is the condensate pipe and inlet gas pressure.
The condensate pipe would be the main culprit here. It’s the condensate pipe that vents condensed flue gases from your boiler. They freeze easily, and when they do, they can cause a blockage. Your boiler is going to quickly recognise that no further condensed gases can exit via the condensate pipe because of the blockage, and the boiler will lock out.
Fixing a frozen condensate pipe is simple; your boiler engineer needs to thaw out the pipe.
What could be wrong with the flue that causes the F4 fault code to be displayed
Like the condensate pipe, if there’s a blockage in the flue, the boiler will lock out. However, it’s unlikely gases have frozen to cause a blockage. On rare occasions, old flues have been known to collapse, essentially, blocking themselves.
However, it’s more likely that a vertical flue has been fitted without a flue guard, and debris is blocking the flue. Your engineer will need to remove the blockage and fit a flue guard to prevent this from happening again.
How does gas pressure affect my boiler’s ability to operate
If gas pressure isn’t high enough, your boiler is going to lock out. And, there’s a few reasons that this might be the case.
The first, is because the gas pressure isn’t high enough into the meter. Unfortunately, that’s a problem that needs to be fixed by your utility provider.
But, a more likely cause of low gas pressure, is due to the regulator on your meter. In freezing conditions, like a condensate pipe, they can freeze. If your gas meter is exposed to the elements, it needs to be boxed in and protected, to ensure that it doesn’t freeze over again.
My boiler engineer thinks the problem is with the gas valve, could this be right
If the burner in your boiler isn’t being provided with enough gas, then it’s not going to ignite, and that results in an ignition fault.
As gas valves are mechanical parts, they can wear over time. As they wear, they start to stick. If your boiler is lacking in gas supply, it’s likely that the valve is sticking, slightly closed, when it should be fully open.
In some instances, your boiler engineer will be able to free the valve. But, if they’re not confident that the valve won’t stick again, a replacement is going to be needed.
But, not all gas valve problems relate to sticking valves. Sometimes, the issue can be something as simple as incorrect adjustment, and this is a quick and easy fix.
If none of the above manages to fix the F4 fault code, your engineer needs to test the valve for power. The wiring and connections to and from the PCB also need to be checked. The culprits will need to be replaced for the F4 fault code to be cleared from the display panel.
I need a new gas valve on my boiler, how much is it going to cost
If your boiler repair company has explored all the options, including wiring, connections, freeing a sticking valve and adjustment, a new valve needs to be fitted.
Typically, you should expect to pay somewhere in the region of £300 for a replacement gas valve, which includes parts and labour.
What happens if the burner on my Glow-Worm boiler is blocked
The next stage is to check the burner. Any combustible material is going to leave behind some level of debris, including gas. And, although this isn’t always a problem, it can be if it finds its way into the jet.
The jet that supplies gas to the burner is extremely small, and incredibly fragile. That means that even the smallest hint of debris, can easily block the jet. That’s going to remove its ability to provide gas to the burner, and result in an ignition failure.
Luckily, a new burner isn’t going to be needed if the jet is blocked. Your boiler engineer can remove the jet, clean it, refit it, and then reset your boiler to clear the F4 fault code from the display panel.
Which electrical parts need to be inspected, that help a boiler to ignite
So far, we’ve covered components that contribute to expelling flue gases, and supplying the boiler with fuel. But, if there’s an ignition fault on your boiler, the culprit could be the ignition lead, probe or even the spark generator.
Your boiler engineer will need to check each component, but also the wiring and connections to them. Any faulty component is going to need to be replaced, otherwise your boiler is going to fail to ignite.
What else does my boiler engineer need to check to clear the F4 fault code
Even if your boiler engineer has fixed a problem mentioned above, that doesn’t mean that’s the only problem with your boiler.
A few other components they’ll need to check include the PCB, air pressure switch and even the fan.
Your boiler won’t ignite unless the air pressure switch tells the PCB that the fan is operational. And that means a fault with any one of these three components, could result in a boiler failing to ignite.
Like other electrical components in your boiler, your Gas Safe repair company can test them using a multi-meter. Any poor wiring or connections will result in intermittent signals being passed between components. And, intermittent signals lead to intermittent boiler operation.
How do I know if I need a new boiler
Finally, before you repair your boiler, you need a comprehensive assessment of the problems it has. Your boiler repair company will be able to assess expensive components such as the PCB, heat exchanger, pump, fan, air pressure switch and even the pump. From this assessment, they’ll be able to determine if the most cost-effective solution is to repair the boiler, or to replace it.
Other Glow Worm boiler issues
For more boiler issues regarding the Glow Worm then please visit the Glow Worm Boiler Problems And Cures page.