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Common Ideal Boilers’ Problems [And How to Fix Them]

Ideal Boilers are well-known in the UK for creating quality boilers. However, they weren’t always like this. The older range (going back 10-15 years) were quite unreliable, so we are called to service Ideal boilers with problems on a regular basis.

In this guide, we’ll cover the most common fault codes you may see when Ideal boilers have problems.

Ideal Boilers Problems

No Time to Read? Here Are the 10 Most Common Ideal Boiler Faults

Below are the most common Ideal boiler problems, along with the corresponding error codes:

  1. Unresponsive boiler
  2. Boiler makes strange noises and leaks
  3. Ignition failures
  4. Leaky boiler
  5. Big bang when boiler turns on
  6. Overheating boiler
  7. Boiler flame loss
  8. Malfunctioning fan
  9. Boiler PCB fault 
  10. Low mains voltage

Is Your Ideal Boiler Due for a Replacement?

As we mentioned above, in many cases a Gas Safe registered boiler repair specialist will need to come in to resolve your boiler’s problems. And their services aren’t cheap. So, if your Ideal boiler keeps malfunctioning, you’ll be forking over lots of money for repairs.

Now, if your boiler is out of warranty and the repair bills keep mounting, it may be best to consider a replacement.

One of the cheapest places to get a new boiler installed is Heatable. Having great connections with most of the best boiler manufacturers, Heatable can offer some incredible deals on new boilers. You can get a range of fixed-price boiler quotes on the screen using their handy boiler installation quote form.

Common Ideal Boiler Error Codes and Problems

Below, we’ll walk you through some common Ideal boiler problems and fault codes that may correspond to the issue at hand. We’ll show you possible fault codes on newer models, like the Ideal Logic Combi 30, and older ones — like Logic Isar.

Keep in mind that whilst there’s a high likelihood of seeing these fault codes when the specified problem occurs, sometimes your boiler may show you a different code in response to the issue.

Ideal Boiler Problem 1: Boiler Unresponsive

Possible Fault Codes

  • On newer models, like the Ideal Logic Combi 30: F9, C0, C2
  • On older, troublesome models, like Logic Isar: No display

One of the common faults we are called out to with the Ideal Boilers is the boiler is completely unresponsive. By this, we mean that it doesn’t even seem to turn on.

This might seem like the boiler has completely given up but usually it’s a simple wiring issue.

Fixing an Unresponsive Boiler

The most obvious thing to do is the check the electrical issue isn’t related to the plug socket. Test this by trying another plug, or testing another appliance in that socket.

Next, a multimeter can be used to check voltages throughout the boiler’s circuit. In many cases, a simple upgrade in the wiring is enough to get the boiler working again.

If the wiring seems fine, the problem is likely to be found at the PCB. The PCB is the heart of the boiler, much like an ECU in a car. Because they are such complicated components, they are usually replaced completely.

The cost of a PCB replacement including labour will depend on the model of the boiler. In general, £275-400 would be a reasonable expectation.

If your boiler is incredibly old (8-10 years or older) it might be worth considering a replacement. You can get prices on-screen using this clickable form from Heatable. Or, jump over to our guide covering boiler installation costs here.

Ideal Boiler Problem 2: Boiler Makes Strange Noises and Leaks

Possible Fault Codes

  • Newer models: L2
  • Older models: L-F

Bear in mind, not only Ideal Boilers have these problems. If the noises sound like liquids trying to escape, and there’s water under the boiler, the most common culprit is the condensate trap.

Over time, debris builds up in the traps, eventually clogging the pipe.

Luckily, it’s a pretty simple problem to fix.

Fixing a Blocked Condensate Trap

The condensate trap can be located underneath the boiler. They are easily removed and it’s a simple case of removing any debris from the trap, cleaning it out and then replacing it.

As we are dealing with liquids, it makes sense to turn the boiler off. Also, the trap may leak, so putting a bowl under the boiler is certainly a good idea.

Ideal Boiler Problem 3: Boiler Ignition Failures

Possible Fault Codes

  • Newer models: L2
  • Older models: L-F

All boilers have a built-in safety mechanism. As one precautionary measure, boilers tend to enter the safety lock out mode after 3 failed ignition attempts. There is usuall a reset button, but you shouldn’t reset your boiler until the fault is found and fixed, as the boiler may still be dangerous to operate.

Fixing Ignition Problems

You’ll need to call a Gas Safe registered engineer. If the boiler is not igniting at all, faulty ignition leads are a likely cause.

If the boiler is trying to ignite (so the ignition leads are working correctly), the sensors on the boiler may be the problem. Boilers have a flame and ignition sensor. Over the years, they can get carbon deposits and other debris on them. Eventually, this build-up will block them to a point where they are no longer functional.

Sometimes, cleaning the sensors will fix the problem. However, it makes much more sense to replace them.

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Ideal Boiler Problem 4: Leaky Boiler

Possible Fault Codes

  • Newer models: F1
  • Older models: L-A

A lot of articles online suggest that a leaking boiler will relate to a broken heat exchanger. This can be the case, but is not the only potential cause. The reason I say this is because a heat exchanger including labour can cost as much as £600 (it depends on the exact model you have).

Hopefully the problem is a lot less serious. We’ve come across many boilers that are leaking and found a common cause is the central heating pump. Older pumps are nowhere near as reliable as new ones. As the boiler vibrates, they can work themselves loose or split a seal. And this could be the cause of your leak.

Fixing a Leaky Boiler

A broken heat exchanger is bad news. Unless you can source a cheap heat exchanger, a new boiler installation is likely the best route.

Hopefully, the problem lies with the pump. If you’re lucky, it’s come slightly loose and water is escaping. Simply tightening the pump to where it secures itself to the boiler could be enough to stop the leak.

If this doesn’t fix the leak, you may also have a faulty seal. In this event, you’ll have to install a new pump. For reference, a new Grundfos pump should set you back around £250.

Ideal Boiler Problem 5: Big Bang When Boiler Turns On

Possible Fault Codes

  • Newer models: L6 or none
  • Older models: none

If this is a problem, no doubt it’s given you quite a scare on more than one occasion!

From our experience, this is common with the Response, Isar and Icos boilers. What’s happening is there is an excess amount of gas prior to ignition. When the boiler eventually fires (probably on the 2nd or 3rd attempt), there is a mini explosion.

Fixing a Banging Boiler

The most likely cause of the banging and excess gas on ignition is the flame sensor. When a flame is not detected properly, the boiler will not function the way it should. Have a Gas Safe registered engineer check the flame sensor as well as the ignition leads.

Once that has been checked/replaced, they will need to ensure everything else in the boiler is set correctly. This means ensuring the correct amount of gas is entering the chamber (this is adjusted using the gas valve) and adjusting the fan speed.

As this relates to gas, only Gas Safe boiler engineers can investigate this particular boiler fault.

Ideal Boiler Problem 6: Boiler Overheating

Possible Fault Codes

  • Newer models: L9/H9/HA/LA
  • Older models: L-A

Like all heating systems in hard water areas, Ideal boilers have problems with limescale build-up. When these mineral deposits accumulate in the heat exchanger, they restrict water flow and cause the boiler to overheat. If this happens, you may hear the kettling noise and see the fault codes above. These debris buildup issues are so common in boilers that even the most comprehensive boiler cover plans don’t include repairs for them.

That said, a few other issues could be lurking in you system and cause your boiler to overheat. These include:

  • Low water pressure due to a leak
  • A blockage in the system
  • Flow thermistor fault
  • Malfunctioning central heating pump

Fixing an Overheating Boiler

Unless you can identify the leak — which can be anywhere in your network of pipes and radiators, or the boiler itself — you’ll need a Gas Safe registered engineer to investigate this problem. In the best case scenario, they’ll either:

  • Find and fix the leak, allowing water pressure to climb back to normal levels
  • Remove debris that’s causing the blockage in the central heating system
  • Replace your faulty thermistor
  • Get the pump rotor spinning

FURTHER READING: You can read more about boiler pressure issues in our guide here.

However, if the Gas Safe registered engineer discovers limescale build-up in the heat exchanger, you may be in for some expensive repairs. In the event that the heat exchanger is no longer salvageable, you may have to replace the boiler altogether.

Ideal Boiler Problem 7: Boiler Flame Loss

Possible Fault Codes

  • Newer models: F2
  • Older models: n/a

If your Ideal boiler can loses its flame during operation, you’ve got a potentially dangerous situation on your hands. So, if you see the Logic F2 fault show up on the display, call a Gas Safe engineer to investigate the issue without delay. There’s a range of underlying causes they may discover, such as:

  • Faulty gas valve
  • Incorrect gas pressure
  • Issue with the flue
  • Malfunctioning fan
  • Lack of gas supply to the property (other gas appliances not working)

Fixing a Boiler With Flame Loss

If all your gas appliances aren’t working, then your property is probably cut off from gas altogether. You can top up your pre-payment meter, or contact your gas supplier — it’s probably their fault, not your boiler’s.

However, if there’s another root cause present, the fix may be as simple as unclogging the flue, or as complex as replacing your boiler. The latter is always a possibility if you’ve got an older Ideal boiler that’s experiencing flame loss often.

Ideal Boiler Problem 8: Boiler Fan Fault

Possible Fault Codes

  • Newer models: F3
  • Older models: n/a

Boiler fans expel toxic fumes out through the flue and to the outdoors. So when a fan fails, the boiler can longer operate in a safe manner. The boiler’s air pressure switch picks up the lack of pressure, and the PCB locks the boiler out as a precaution.

You can read more about boiler fan faults here, but in a nutshell, these problems can arise for a number of reasons, like the fan coming loose or sustaining damage. In some cases, the issue may stem from faulty wiring, or PCB problems.

Fixing a Boiler With a Fan Fault

Because apparent fan faults can point to other problems with the boiler’s components, it’s always best to get a Gas Safe engineer to diagnose the problem.

If the fan is simply stuck, then lucky you — the fix is simple and inexpensive. But if you have to replace the fan, or worse, get a new PCB, you could be looking at a bill of £200-£500, with parts and labour. If your boiler is old and out of warranty, getting a replacement may end up being cheaper than dealing with constant repairs.

Ideal Boiler Problem 9: PCB Fault

Possible Fault Codes

  • Newer Models: F9
  • Older Models: No Display

The PCB (Printed Circuit Board), is the boiler’s “brain” — this is where all the internal components communicate amongst each other. When the PCB develops a fault, your boiler is in deep trouble; simply put, it stops operating properly.

All the symptoms of a faulty PCB are too many to list, but some common ones include:

  • Display panel turning on and off
  • Burning smell coming from the boiler
  • Boiler operates sporadically

You can learn more about these symptoms and possible fixes in our detailed guide to boiler PCB faults.

Fixing a Boiler PCB Fault

Your Gas Safe engineer will have to tell you what’s happened to the PCB. In a disaster scenario, you may have to replace your PCB; and unfortunately, these components aren’t cheap. As we mentioned above, installing a new boiler might make more long-term financial sense than getting your old boiler a brand-new PCB.

Ideal Boiler Problem 10: Low Mains Voltage

Possible Fault Codes

  • Newer Models: F7
  • Older Models: n/a

The most likely cause of the Ideal F7 fault code actually has nothing to do with the boiler itself. Chances are, there’s an issue with the supply of electricity to your property. However, this error code can also point to an underlying issue with the PCB.

For safety reasons, Ideal boilers will lock out after detecting low mains voltage. This means you won’t be able to get your boiler working again until you sort out the problem.

Fixing Boiler Low Mains Voltage

The first thing you should do, is contact your electricity supplier. If everything turns out to be fine with your mains electricity, then ask a Gas Safe engineer to diagnose your boiler.

Ideal Boiler Still Not Working?

It can be extremely frustrating dealing with boiler faults that don’t seem to stop. Just because you have a fault doesn’t automatically mean you need a replacement. A Gas Safe engineer will advise on the best route to take.

And, if your Gas Safe engineer thinks your boiler is on the blink, get your fixed price from Heatable for a new one here.

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If your Ideal Boiler fault code has not been covered above, please leave a comment and we’ll do our best to get back to you.




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