What does E1 mean on your boiler? Here we explain what it can mean and how to resolve it.
Is your boiler unexpectedly flashing the E1 Boiler Fault Code?
Are you unsure what it means and how to deal with it? No worries, we've got it covered...
In this guide, we explain the most common causes of the E1 Boiler Fault Code, how it affects your boiler - and how to resolve it in the fastest possible manner.
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Key points:
• E1 Error Code: Typically indicates low water pressure in the boiler system, a common issue that can cause the boiler to shut down.
• Common Causes: Includes water leaks, recently bled radiators or a faulty pressure relief valve.
• Basic Fix: Repressurise the boiler by adding water through the filling loop, aiming for a pressure reading between 1 and 1.5 bar (instructions explained below).
• Professional Help: If the issue persists after repressurising, contact a Gas Safe registered engineer.
What Causes the E1 Boiler Fault Code?
The E1 Error Code is a common issue on boilers and typically isn’t too serious. It usually indicates low water pressure, which causes the boiler to lock out and stop working.
You can check if this is the case by looking at your boiler’s pressure gauge, which looks like this:
Patrick Garner/Heatable
If you see the E1 code, the fix is often as simple as repressurising your boiler, which is a straightforward process (detailed step-by-step instructions are provided below). However, the E1 Error Code can sometimes signal other issues that may require diagnosis and repair by a Gas Safe engineer.
To better understand the specific problem, pay attention to the digits following “E1,” as these can help identify the root cause:
• E119: Indicates low water pressure, the most common issue. Repressurising the system usually resolves this.
• E133: Points to a gas supply fault. Ensure the gas supply is active and reset the system. If the issue persists, contact your installer.
• E168: Suggests the boiler has detected an issue but cannot pinpoint the exact source. Further inspection may be necessary.
When the E1 Error Code appears, it’s natural to be concerned, but it often indicates a low-pressure issue that you can resolve without professional help.
If low pressure isn’t the problem or if you’re unsure, it’s advisable to contact a certified Gas Safe engineer.
Below, we explore the E1 Error Code in detail, including its causes and solutions, to help you accurately diagnose and fix the issue.
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Fixing the E1 Boiler Fault Code
Any boiler showing the E1 fault code means that a significant pressure drop has occurred in the system. The fix is to repressurise your boiler.
When your boiler is switched off, the pressure gauge should read around 1 Bar – in the green zone on the gauge.
When it is in operation (demanding heat/hot water), its pressure will increase slightly, then it should drop back down.
However, in the case of the E1 fault code being displayed, your pressure will be low, indicated on the pressure gauge as being in the lower red zone.
As repressurising the system is not a very complicated job, it's a good idea to get used to the process, which is a DIY task.
However, if the pressure unexpectedly drops again, this is a strong indication that there is a leak or flaw in your boiler. This, of course, will require further help from a qualified Gas Safe Engineer.
If low pressure is indeed the root of the problem, it can be dealt with by following the steps below in order to re-pressurise your boiler.
How to top-up (repressurise) your boiler
In most cases, boiler pressure (if it's too low) can be resurrected at home easily and typically takes a minute or two, here’s how:
Step 1 - Find your filling loop
Directly underneath your gas boiler should be some pipework, amongst which will be your filling loop.
The filling loop is the silver flexi pipe with either one or two black (usually) taps on.
Patrick Garner/Heatable
Step 2 - Increase the pressure
To increase the pressure, you’ll need to open your one (or two) taps, full until they lock at 45 degrees. As you’re doing this, you should see the pressure rise on the boiler’s pressure gauge to around 1 bar. Ta-da, your boiler has been repressurised.
Prefer video? We have created a step-by-step video guide on how to top up your boiler pressure below:
Step 3 - When you're in the green, close the taps
Once it’s back in that oh so reassuring green zone – close the taps again – ensuring they’re fully closed back to their original position.
Accidently leaving them open would put your boiler under more pressure than Theresa May is to deliver a hard Brexit.
Boiler keeps losing pressure, even after being repressurised?
If your boiler is losing pressure quicker, and more regularly than Manchester UTD lost league places after the departure of Sir Alex Ferguson, then something is not quite right.
Could the pressure dropping be a sign of something more serious that may warrant a new boiler? Read our quick guide on how to tell if your boiler needs replacing here.
And if you're just curious to see how much a new boiler will cost complete this quick questionnaire to find out for free.
If your boiler is constantly losing pressure, check out our full guide on potential causes of low boiler pressure.
Moreover, E1 does not necessarily or usually mean you need a new boiler.
It does however mean that you should consider the fact that your old boiler is costing you unnecessary extra money. If the repair bills start to ring up, it may simply be better to get a replacement boiler.
If you have repressurised your boiler several times and are facing the same fault code, it may be worth considering getting a new boiler that can save you money on your monthly gas bill and prevent future problems altogether.
Alternatively, if you’re still facing the same fault code, then you can get the help of a heating engineer to help solve the E1 problem.
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