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Ideal Boiler FN Fault Code


The Ideal fault code FN flame loss during operation Q & A or require an engineer for an emergency boiler repair.


The Ideal Boiler Fault Code FN Error Common Q & A


Just below, we have a list of common questions relating to the FN fault code on the Ideal boiler.

Ideal Boiler FN Fault Code
  • What does the FN fault code mean on my Ideal boiler?
  • What can cause the FN fault code to be displayed?
  • Can the FN fault code on Ideal boilers be fixed on a DIY basis?
  • Will resetting my boiler fix the FN fault code?
  • If there’s a gas supply issue, how will the boiler engineer know?
  • The boiler is getting enough gas pressure, so what else will they need to look for?
  • What problems will my boiler engineer be looking for on the gas valve?
  • Will I need a new gas valve if this is causing the problem with the gas supply?
  • How much will it cost to fit a new gas valve and clear the FN fault code?
  • Why would the connections and wires on my boiler’s gas valve be damaged?
  • What happens if the gas valve is sticking?
  • Can a sticking gas valve be fixed?
  • What is a condensate, and how would this contribute to flame loss and the FN fault code being displayed?
  • What can cause electrode faults on my boiler?
  • If the gas valve or electrodes have moisture damage, how can we find the cause of the problem?
  • What should I do if I have water damage in my boiler?

What does the FN fault code mean on my Ideal boiler


The Ideal boiler FN fault code relates to a flame loss during operation.

Ideal boilers have a fault code system that is monitored by the printed circuit board (PCB). The PCB gets various readings such as air pressure, water pressure and temperatures from a range of sensors. It can monitor the boiler’s operation using these sensors, to check it’s operating safely.

One of these sensors is the flame sensor. If the PCB gets a signal to say that the flame has gone out from this sensor, it will lock out the boiler and show the LN or FN fault code on the display panel.

What can cause the FN fault code to be displayed


Although fault codes help to narrow down the problem, they don’t highlight the exact problem. In this case, it’s most likely that there’s a problem with the gas supply.

However, the problem could also be with:

  • Condensate blockage
  • Ignition electrode and detection electrode faults

Can the FN fault code on Ideal boilers be fixed on a DIY basis


In this case, there isn’t a simple DIY fix for your boiler. And, you shouldn’t try to fix the FN fault code on your Ideal boiler unless you are Gas Safe registered.

There’s a good chance that this is a gas related fault, and that could mean DIY repairs make the boiler more dangerous than it already is. Instead of attempting a DIY fix, you should speak to an emergency boiler repair engineer to find the fault and fix it on your behalf.

Will resetting my boiler fix the FN fault code


A reset won’t fix the problem. On the off chance that the reset tricks your boiler into working for a few minutes, before locking out again, you could be running a boiler that is dangerous.

So, don’t reset the boiler. This should only be done when a Gas Safe engineer has fixed the problem.

If there’s a gas supply issue, how will the boiler engineer know


There are a couple of tests that your heating engineer will need to run. The first is to check that there is pressure at the gas meter. If there’s not pressure at the meter, they’ll need to find and fix the fault.

Beyond an actual supply issue from the utility provider, there’s a good chance it’s the regulator on the gas meter that is causing the issue. But, if your heating engineer has determined that there is gas coming from the meter, they’ll then need to run a test on the boiler.

The gas inlet on the boiler should be supplied with gas at 18mbar of pressure. If this isn’t the case, there’s not going to be sufficient gas to keep your boiler running and that’s going to result in flame loss.

The boiler is getting enough gas pressure, so what else will they need to look for


If there is gas pressure to the meter and the boiler, the next place to look is the gas valve.

The gas valve on your boiler monitors the flow of fuel to the burner. When the PCB sees you’ve called for heating or hot water, it tells the gas valve to open.

Of course, if the gas valve is faulty, it might not be responding to this demand from the PCB, which is what could be causing the gas supply issue.

What problems will my boiler engineer be looking for on the gas valve


If your boiler engineer thinks that it’s the gas valve causing the supply issue they’ll check for:

  • Excessive wear
  • Damage to wiring and connections
  • The valve sticking

Will I need a new gas valve if this is causing the problem with the gas supply


Gas valves can wear out over time. If they have excessive wear, damage and are sticking, your valve may need to be replaced. But, on many occasions the valve can be reconditioned and refitted, rather than a replacement being needed.

How much will it cost to fit a new gas valve and clear the FN fault code


Sometimes, replacing the gas valve is going to be unavoidable. If your emergency repair engineer thinks the valve needs replacing, you should expect to pay somewhere in the region of £250-300 including parts and labour.

Why would the connections and wires on my boiler’s gas valve be damaged


When nothing seems obvious from a visual inspection, your boiler engineer will be able to check the gas valve’s wiring and connections using a multi-meter. On many occasions, it’s a simple case of loose connections and/or wiring that are causing the problems.

If the wiring and connections between the PCB and gas valve are loose, signals being given/received are going to be intermittent. And, that’s going to result in the gas valve opening/closing when it shouldn’t, or not responding at all.

Damage can also come in the form of boiler leaks. But, it might be a simple case of long-term boiler vibrations that have caused the connections to work loose.

What happens if the gas valve is sticking


The PCB is going to tell the gas valve when to open, and when to close. If a valve is worn, it could be sticking. And, when it does, it might not fully close, or fully open.

In the case of the FN fault code on Ideal boilers, it’s likely that it’s stuck closed, or not opening as much as it should. This is limiting the flow of gas to a point where there is flame loss; there’s not enough fuel to keep the burner going.

Can a sticking gas valve be fixed


Your emergency boiler engineer should be able to free the gas valve on most occasions. That’s going to mean you avoid a replacement and therefore repair costs of £300 or more. But, if they’re not happy that the valve is 100% free, it might be that a replacement is needed.

What is a condensate, and how would this contribute to flame loss and the FN fault code being displayed


The condensate pipe is what vents condensed gases from your boiler. If this is blocked, the air pressure switch notices these gases aren’t being expelled. That’s going to lead to your boiler locking out.

A boiler repair engineer needs to check the condensate for blockages. Sometimes small pieces of debris are all that’s needed to change the air pressure enough for a lock out to occur. However, if it’s below freezing, there’s a good chance that the pipe has frozen.

All your boiler engineer needs to do, is to thaw out the pipe on your boiler.

What can cause electrode faults on my boiler


Besides these components simply wearing out due to old age, there’s a good chance that they’ve been exposed to moisture. If they’re exposed to moisture, the boiler is going to fire up and operate intermittently.

If the gas valve or electrodes have moisture damage, how can we find the cause of the problem


If you’ve noticed moisture on the electrodes, there’s a good chance this has come from a boiler leak, however small.

Leaks don’t have to drip directly onto electrical components to cause damage. As a boiler heats up, it will condense any water from this leak, and this condensed moisture can then settle on components.

Typical signs of moisture damage would be an intermittent boiler that cycles on and off randomly. And when your boiler engineer inspects the boiler, they’ll notice connections being burnt out where moisture has been present.

What should I do if I have water damage in my boiler


If water damage has caused damage to any component in your boiler, the priority is to get this fixed as soon as possible. Water damage can kill boiler parts to a point where there’s little point doing any repairs. The list of repairs amount to so much, it makes more sense to invest in a new boiler.

One of the most important parts in your boiler is the PCB. If this gets water damage, you could be looking at a repair bill that’s over £500.

So, the leak fixed as soon as possible, and then get the gas supply issue rectified.

Other Ideal boiler issues


For more boiler issues regarding the Idea Boiler then please visit the Ideal Boiler Problems And Cures page.