Glow-Worm Boiler F16 Fault Code
The Glow-Worm fault code F16 related to a flame detection fault and here we have Q & A or require an engineer for an emergency boiler repair.
The Glow-Worm Boiler Fault Code F16 Error Common Q & A
Just below, we have a list of common questions relating to the F16 fault code on the Glow-Worm Boiler.
- What does the F16 fault code mean on my Glow-Worm boiler?
- What is a flame detection fault?
- Can I fix the F16 fault code on my Glow-Worm boiler on a DIY basis?
- What are the most likely issues that are causing the F16 fault code to be displayed?
- How can my boiler engineer check to see if the flame sensor is causing problems?
- How could the PCB contribute to a flame detection fault?
- If the ignition lead is at fault, how much will it cost to replace?
- How can moisture affect electronic components in my Glow-Worm boiler?
- What does gas pressure have to do with a flame detection fault?
- How can a blockage in the flue or condensate pipe cause a flame fault?
- Could the burner’s jet cause the F16 fault code to be displayed on my Glow-Worm boiler?
- How will my boiler engineer know if the gas valve is to blame?
What does the F16 fault code mean on my Glow-Worm boiler
If you’re having problems with your Glow-Worm boiler, a fault code will be displayed on the control panel. In the case of the F16 fault code, the problem here is a flame detection fault.
What is a flame detection fault
When you turn on taps, showers, or heating, the printed circuit board PCB recognises the demand for heat and tells the burner to fire up. To do so, the gas valve supplies fuel, via a small jet.
But, if the F16 fault code is being displayed, there’s either a problem that means the flame isn’t present, or there isn’t a signal being passed on to the PCB. The PCB recognises that the flame isn’t present when it should be, and that’s going to lead to the boiler locking out.
Can I fix the F16 fault code on my Glow-Worm boiler on a DIY basis
You shouldn’t attempt to fix the F16 fault on a DIY basis. There are very few faults that can be fixed, without the help of a Gas Safe registered boiler repair company.
An emergency repair company will be able to fault find and figure out what the problem is. This is a job only for those that are qualified to work on gas appliances.
Once they’ve fixed the issue, they’ll reset your boiler. With the problem fixed, that’s going to clear the fault code from the display panel.
What are the most likely issues that are causing the F16 fault code to be displayed
There are two separate fault-finding missions for your boiler repair company to complete. The first, relates to anything that could cause the boiler not to recognise a flame, even though it’s present.
This is the most likely cause of the flame detection fault, and that includes:
- Damage to the flame sensor
- Faults with the PCB
If neither of these yield results, they’ll want to focus on parts are could affect the boiler’s ability to produce a stable flame.
If the boiler isn’t producing a stable flame, it will lock out. And, that’s because the boiler’s PCB is recognising a weak or non-existent flame, when there should be one.
That includes:
- Ignition leads
- Moisture on any electronic components
- Incorrect gas pressure
- A blockage in the flue or condensate pipe
- Blocked burner jet
- Gas valve faults
As you can see, this can be a long and complicated process.
How can my boiler engineer check to see if the flame sensor is causing problems
The most obvious cause of a flame detection fault is one with the component that detects the flame; the flame sensor.
If your flame sensor isn’t working correctly, it’s going to be passing on signals to the PCB that are incorrect. That might mean the PCB gets a signal to say the flame is present (or not), when the opposite is true. The PCB relies on this sensor to know when a flame is active, so if it’s not receiving the correct signals, it’s going to lock out the boiler until the problem is fixed.
Luckily, your emergency boiler repair company will be able to check the flame sensor quickly. Using a multi-meter, they’ll be able to test for power. Assuming all connections are secure, and wires are in good condition, if power isn’t present, they’ll need to replace the flame sensor on your Glow-Worm boiler.
How could the PCB contribute to a flame detection fault
And these sensing issues can go both ways. Just as when the flame sensor is faulty, the PCB will be given the wrong signals, it might be that the PCB is faulty and isn’t understanding these signals correctly. So, even though the flame sensor is showing the correct signal (for instance, the flame is active), the PCB isn’t recognising that fact.
Like the flame sensor, your boiler engineer will want to test connections to the PCB, securing loose connections where necessary. And, after testing the wiring to the PCB, they’ll want to test the PCB for power.
If the PCB is the problem, it’s going to need to be replaced. Unfortunately, these aren’t cheap components to install. A typical PCB replacement could sit anywhere between £400-500.
If the ignition lead is at fault, how much will it cost to replace
You should expect the ignition lead to cost around £200 to replace. Like all other electronic components, they’ll need to be tested first, to ensure that this is the problem at hand. If this is the problem, the ignition sequence isn’t going to be successful. With gas being supplied by the valve, but not being burnt, the boiler is going to need to lock out, otherwise, it could be dangerous.
How can moisture affect electronic components in my Glow-Worm boiler
A huge amount of damage can be caused to the internal components of your boiler, with just a small amount of moisture. This is particularly the case with older boilers, whereby the electronic components aren’t sealed as well as they might be on newer models.
Typically, we find that most boilers that suffer from moisture damage, have a leaking pump. It might be the pump is just old, or it’s blocked. Most of the time, this results in the seals on pump blowing, and this leads to water leaking from the pump, directly onto components in the boiler.
Naturally, your boiler engineer is going to need to fix the pump, as well as any damage to the electronics that it’s caused.
When caught early enough, water damage repairs might be a case of replacing some cheap components, as well as small sections of wiring. The sooner water damage is dealt with, the better. Because, any component that meets with water, is likely to fail soon.
What does gas pressure have to do with a flame detection fault
Without the correct gas pressure feeding your appliance, the flame signal is going to fluctuate, and sometimes, be non-existent. The flame sensor will notice instantly, pass on this information to your boiler’s PCB, and your boiler will stop working.
You’ll need to get your boiler engineer to check the gas pressure into the meter, out of the meter, and into the boiler. They’ll then be able to see if there’s a lack of gas pressure at any point.
How can a blockage in the flue or condensate pipe cause a flame fault
Your flue vents harmful gases from your boiler. And, your condensate pipe does the same, but with condensed gases. If either of these are blocked, the boiler is no longer safe, and shouldn’t be running. That’s going to result in the flame going out, and the boiler locking out.
It’s rare that a flue blockage is the cause, unless you have a vertical flue that’s not been fitted with a flue guard; debris might have found its way in. If this is the case, the flue needs to be cleared and the boiler reset.
A more likely cause is a blocked condensate pipe, especially in winter months. The gases in this pipe can easily freeze, blocking the pipe completely. Your boiler repair company will need to thaw out the pipe, before resetting the boiler.
Could the burner’s jet cause the F16 fault code to be displayed on my Glow-Worm boiler
The jet on your boiler’s burner is incredibly small. And that means, the tiniest amount of carbon, could block it completely. That means gas can no longer reach the burner, and the flame is going to go out. The flame sensor is going to (correctly), log a flame detection fault with the PCB.
On most occasions, the fix is simple; clean out the burner’s jet and refit it.
How will my boiler engineer know if the gas valve is to blame
Finally, your boiler engineer will want to check out the gas valve. It’s the gas valve that controls the flow of gas to the burner. That’s going to increase when you turn up your heating thermostat, and vice-versa.
The most common problem with gas valves, is that they stick. This is a fault that comes with general wear and tear. In this case, it’s likely that the gas valve is stuck closed, even when the PCB is telling it to open. Sufficient amounts of gas aren’t being allowed into the burner, and that means that the burner’s flame is going to be intermittent at best.
On some occasions, the valve can be freed, so that it’s not sticking. But, when the valve can’t be freed, a replacement is going to be needed. And, a replacement gas valve is likely to cost somewhere in the region of £300.
Other Glow Worm boiler issues
For more boiler issues regarding the Glow Worm then please visit the Glow Worm Boiler Problems And Cures page.