Glow-Worm Boiler F18 Fault Code
The Glow-Worm fault code F18 relates to a user interface fault and here we have Q & A or require an engineer for an emergency boiler repair.
The Glow-Worm Boiler Fault Code F18 Error Common Q & A
Just below, we have a list of common questions relating to the F18 fault code on the Glow-Worm Boiler.
- What does the F18 fault code mean on my Glow-Worm boiler?
- Will resetting my boiler fix the fault?
- What could have caused the F18 fault code to be displayed?
- If wiring and connections are loose or damaged, how will this affect my boiler?
- What is most likely to cause excessive boiler vibrations?
- How can small leaks lead to the F18 fault code being displayed?
- What can be done to prevent this from happening again?
- How can the boiler chip card cause a user interface error?
- How will my boiler engineer know if my PCB is faulty?
- How much is it going to cost to replace the PCB on my Glow-Worm boiler?
- Is it worth investing in a new boiler?
What does the F18 fault code mean on my Glow-Worm boiler
If the F18 fault code is being shown on the display panel of your Glow-Worm boiler, it means there’s a user interface fault.
Your boiler has an integrated fault code system for two reasons. The first, is to ensure that the boiler doesn’t operate dangerously when there’s a problem. So, when the printed circuit board (PCB) notices that there’s a potentially dangerous problem, it locks out and displays a fault code, F18 in this case.
The other reason is to ensure internal components aren’t subject to damage.
Not all fault codes lead to a boiler locking out, it might still work intermittently. But, the fault code is still important. It allows a Gas Safe engineer to determine what the problem is quickly, and that means less money spent on repairs.
Will resetting my boiler fix the fault
Resetting your boiler won’t help to fix the F18 fault code on your Glow-Worm boiler. The reset function should only be used when the problem has been fixed, it’s not a way to fix a problem.
As diagnosing and fixing the F18 fault is going to mean taking the boiler apart, you’ll need to call a Gas Safe engineer. It’s only Gas Safe registered engineers that are legally allowed to work on gas appliances.
What could have caused the F18 fault code to be displayed
The first thing your boiler engineer will need to check, is the user interface itself. There’s a chance that this is the component that needs replacing, although typically, it’s usually an issue connected to the main PCB that’s causing the fault code to be displayed.
After discounting the user interface as not being the problem, your boiler engineer is going to need to check the:
- Wiring and connections to the PCB and user interface
- Boiler chip card
- PCB configuration is correct
- PCB isn’t faulty.
If wiring and connections are loose or damaged, how will this affect my boiler
Electrical components in boilers are extremely fragile, and incredibly sensitive. Even one slightly loose connection, or damaged section of wiring, is going to mean that the boiler works intermittently, or not at all.
So, the first job for your boiler engineer, is to check all wiring and connections that link the user interface to the main PCB. They’ll then be able to pin-point where the problems lie (if any), by using a multi-meter.
If there are no signs of physical damage, connections can be secured to fix the problem.
However, loose connections and damaged wires are usually present due to a catalyst. Typically, we find this is either internal boiler vibrations, or small leaks in the appliance.
What is most likely to cause excessive boiler vibrations
There are lots of moving parts in your boiler. And, as with any other moving part, they can wear over time. The pump and fan are common examples that, when worn, can vibrate excessively. This is usually due to the shaft or bearings wearing beyond a point where the component operates fluidly.
This might restrict these components ability to operate. For instance, the pump may struggle to circulate water, causing a circulation fault. And the fan may not be able to create a big enough draft, meaning that flue gases aren’t expelled correctly. In both cases, it’s likely your boiler will lock out.
How can small leaks lead to the F18 fault code being displayed
Leaks need to be fixed quickly. The older your boiler is, the more likely it is that electrical components aren’t 100% sealed. And that means any exposure to water, is going to lead to damage, or in many cases, replacement parts being needed.
Leaks can come from components such as the heat exchanger and pump.
Pumps tend to leak due to seals that have degraded, where as the heat exchanger usually forms a small crack, when exposed to excessive amounts of limescale over prolonged periods.
Even a small leak is enough to damage core components like the PCB, or damage wiring and connections.
What can be done to prevent this from happening again
The first thing to do, is to highlight the wiring and/or connections that are causing the problems and fixing them, so the boiler is electronically, in good condition.
Once these problems have been dealt with, your boiler engineer needs to determine if the cause of the problem was general wear and tear, vibrations, or leaks.
Where vibrations are the issue, it’s likely a service kit for the pump or fan will fix the problem. Replacing the bearings will allow them to run much smoother.
If the pump is in poor condition and needs replacing, you should expect to pay somewhere in the region of £250 for a quality pump such as Grundfos. And, if the fan needs replacing, you should expect to pay around £225-275, depending on the exact fan you need.
If vibrations aren’t the problem, its likely leaks are instead. Where leaks are the issue, the pump’s seals can be replaced. But, the same can’t be said for the heat exchanger. Cracks are rarely fixable, and that’s going to mean replacing the heat exchanger at a cost of over £400.
Typically, all three of the above parts are likely to take around one day to replace.
How can the boiler chip card cause a user interface error
The boiler chip card helps a generic PCB, communicate with your boiler. Manufacturers don’t make a different PCB for each boiler they produce. And, that means they need a piece of technology to make a generic PCB, compatible with lots of different boilers; that’s the boiler chip card’s job.
If you have an incorrect, faulty, or incorrectly installed boiler chip card, your boiler won’t work, and neither with the user interface on the boiler.
Your boiler engineer needs to check the correct boiler chip card is inserted in your boiler, for it to work.
And, they’ll need to ensure that the PCB is configured correctly. If you’ve had a new boiler, or a new PCB, it’s likely that a user interface error is showing, because the PCB hasn’t been setup by your service engineer.
Typically, the setup requires the engineer to key in a code, specific to your appliance.
How will my boiler engineer know if my PCB is faulty
If all else fails, your boiler repair company will need to check to see if it’s the main PCB that’s causing the issue.
The PCB on your boiler controls all the important electrical components. Even a slight fault with the PCB, is going to mean that the boiler works sporadically. As the problem progresses, this might end up with the boiler not working at all.
Like they did when testing wiring and connections, your repair company can use a multi-meter. Testing different points of the PCB, they’ll be able to see if it has power. If the wiring and connections are confirmed as having power, but the PCB isn’t, then it’s going to need to be replaced.
Can my PCB be repaired
Don’t jump to conclusions without having a Gas Safe engineer visit. A PCB is an expensive part to replace. And sometimes, it’s a simple case of securing loose connections, or repairing damaged ones.
How much is it going to cost to replace the PCB on my Glow-Worm boiler
The PCB on your boiler, is the most expensive component to replace. Typically, we’d expect a replacement to be in the £400-500 range. Prices will vary depending on the exact model boiler you have, and therefore what PCB is needed.
Typically, a PCB will be fitted within one day. However, this isn’t a spare part that boiler repair companies have lying around on their van. So, it’s likely you may have to wait 1-2 days for the part to be delivered.
Is it worth investing in a new boiler
Your boiler repair company will be able to help you determine the best route forward. Typically, boiler installation costs start at around £1,800. So, if you’re looking at spending £500+ to fix an old, unreliable and inefficient boiler, it might be worth asking your engineer to give your appliance a health check.
By assessing important components such as the heat exchanger, pump, fan and the PCB, they’ll be able to determine the longevity of your boiler. In many cases, it makes sense to invest this money into a new appliance, with a long warranty, rather than repairing an old boiler.
Other Glow Worm boiler issues
For more boiler issues regarding the Glow Worm then please visit the Glow Worm Boiler Problems And Cures page.