Ideal Logic L1 fault code

Ideal Logic L1 fault code explained

Whilst it is probably not the most common fault code, If you have an Ideal Logic boiler you may experience the L1 fault code at some point.

The L1 fault code will cause your Ideal Logic boiler to stop working entirely, leaving you without central heating or hot water.

If you look in the Ideal Logic installation manual under the L1 fault code it states the following;

“FLOW TEMPERATURE OVERHEAT LOCKOUT“

If you are seeing the L1 fault code on your Ideal boiler, it more than likely means that your boiler has overheated.

Although like a lot of fault codes on Ideal Logic boilers, it doesn’t tell you exactly why it has overheated, as it’s just not possible for the boiler to know exactly why.

Sometimes you may be able to get your boiler working again with a reset once it has cooled down, but a lot of the time the boiler may over heat again and go straight back to the L1 fault code.

In our experience working on Ideal Logic boilers, a lot of the time the L1 fault code is caused by a failed or failing central heating pump.

The pump on modern combination boilers like the Ideal Logic is needed to provide hot water as well as heating. If the pump fails altogether the result is no heating and no hot water.

If your boiler is working fine in central heating mode only, but only coming up with an L1 fault code when running the hot water, then the likely cause of the problem is a blocked plate to plate heat exchanger.

On the Ideal Logic boiler, the plate to plate heat exchanger is a secondary heat exchanger which transfers the heat from the primary heat exchanger to the hot water being delivered to the taps.

This is called an indirect design combination boiler. Most modern combination boilers including every Ideal Logic combination boiler are of this design.

When these plate to plate heat exchangers get blocked they usually affect the hot water. If the blockage is really bad then it can cause your boiler to overheat as well obviously showing an L1 fault code.

When to call a gas engineer to fix your boiler

If you are experiencing the L1 fault code on your Ideal Logic boiler, it is important to take action as soon as possible.

While some issues can be resolved by homeowners themselves, others require the expertise of a qualified Gas Safe registered heating engineer.

A persistent L1 fault code more than likely means your boiler keeps overheating. If this is the case then you are probably best off not trying to keep using the boiler until you can get a professional to have a look. Otherwise you could end up causing more damage to the boiler.

The L1 fault code is often caused by a faulty pump or blocked heat exchanger, but other parts such as a faulty printed circuit board for example could also cause this issue.

This is why it is extremely important to get a suitable heating engineer with experience on Ideal Logic boilers, otherwise you could end up wasting money fitting expensive parts to your boiler that are unnecessary.

So it usually best to get a qualified Gas Safe registered heating engineer to have a look at your boiler at your earliest convenience.

How to prevent the L1 fault code

A lot of the time certain faults on an Ideal Logic boiler can be prevented with regular annual servicing and maintenance by a suitable heating industry professional.

However there is generally not a lot than can be done to prevent the L1 fault code from a service point of view.

A lot of the parts on a Ideal Logic boiler are non serviceable parts, this includes the pump. This means that there is nothing that can be done to these parts to extend the life of the pump and prevent the L1 fault code.

However an experienced engineer used to working Ideal Logic boilers can usually perform a strength test on the pump whilst servicing the boiler.

This will enable them to try and determine if the pump is coming to the end of its life, and recommend replacing it preemptively as a preventive maintenance measure so as to avoid faults such as the L1 fault when you need your boiler the most.

Ideal Logic boilers use high quality Grundfos central heating pumps. These pumps generally have a life span of somewhere between 10 – 15 years. Sometimes these pump can last as long as 20 years or more, depending on how much the boiler is used and how well the boiler has been maintained.

Ideal Logic boilers affected by the L1 fault code

The L1 fault code on Ideal Logic boilers can affect any combination boiler, any system boiler or any heat-only boiler.

Below is a list of Ideal Logic boilers that can be affected by the L1 fault code;

• Ideal Logic Combi C24, C30 and C35 combination boilers
• Ideal Logic + Combi C24, C30 and C35 combination boilers
• Ideal Logic Combi 2 C24, C30 and C35 combination boilers
• Ideal Logic Max Combi C24IE, C30IE and C35IE combination boilers
• Ideal Logic Combi ESP1 26, 33 and 38 combination boilers
• Ideal Logic System 15, 18, 24 and 30 system boilers
• Ideal Logic Heat 12, 15, 18, 24 and 30 heat-only boilers

Frequently asked questions:

Is my boiler showing an L1 fault code worth repairing ?

Yes, most of the time your broken Ideal LogicI boiler displaying an L1 fault code will be worth repairing. Obviously the cost to repair your boiler will be determined by which parts need to be replaced.

You would need a competent, Gas Safe registered heating engineer to have a look at your boiler and make an assessment to determine exactly which parts might need to be replaced.

Before replacing your boiler it is always worth getting a suitable Gas Safe registered heating engineer, with experience working on Ideal Logic boilers, to make an assessment of your boiler so you can determine whether it is worth fixing not.

Can I repair the L1 fault code myself?

No, unfortunately in general an end user will not be able to solve an L1 fault code on their own, with maybe one or two exceptions.

Sometimes on an Ideal Logic an end user can shut off the valve for the return pipe by mistake when trying to add pressure to their boiler.

If your boiler was working fine before you added some pressure to it, then check to make sure you haven’t fiddled with any of the other valves underneath the boiler.

Aside from that repairing the L1 fault code will usually require removing the cover of your Ideal boiler to replace parts which you are not legally allowed to do unless you are a Gas Safe registered heating engineer.

Is the L1 fault code dangerous?

No, in general the L1 fault code on an Ideal Logic boiler is not inherently dangerous.

Modern Ideal boilers are designed with fail safes in place to make sure that the boiler will only work if it safe to do so.

Having said that the L1 fault code means your boiler is probably overheating for some reason, and an overheating boiler in general is not good.

If you are having issues with an intermittent L1 fault code, resetting the boiler is often only a short term solution to your problem at best, and your boiler may stop working altogether at some point.

As such if your boiler is coming up with an L1 fault code, the best thing to do it get it repaired at your earliest convenience, by a suitable Gas Safe registered heating engineer – ideally one that has experience working on Ideal boilers.