How to Fix an E1 Error on a Boiler

Boilers are a staple in any home, therefore ensuring your boiler is in good working order can minimise the risk of breakdowns and being left with the nasty surprise of no hot water.

Whilst keeping your boiler in good working condition is wise, it is also useful to have a good understanding of your boiler overall, as this can help to save you money in the long run. Understanding different error codes can also help to minimise costly call-outs and give you peace of mind.

One of the most common error codes on Baxi, Main, and Potterton boilers is the E1 error code. If your boiler is showing an E1 error code, you may be able to resolve this issue. In this guide, we will explore what to look out for with the E1 error code and how to fix it.

What does an E1 error code mean on a boiler?

Boiler fault codes notifies the user about an issue with the boiler system. Similar to the warning lights on a car dashboard, they alert users to potential problems.

By catching the problem early on, this warning system can help users avert boiler breakdowns and costly repairs. Early notification systems allow minor issues to be resolved by the owner or a Gas Safe-registered engineer.

Error codes will be displayed on the boiler display panel. There is a range of different error codes which help the user understand the potential issue.

Some issues are relatively easy to deal with. In other cases, it is important that a Gas Safe-registered engineer carries out the work. A professional must be used to deal directly with the gas supply.

Boiler fault code types

The following examples of boiler error code types will help you understand the potential problems that can occur.

This can help you determine whether you will be able to resolve the issue yourself. Alternatively, a professional will be needed if the error code signifies a more significant issue with the boiler or gas supply.


An E119 error code on your boiler is relatively common. It is also one of the simplest issues to resolve. This type of error code signifies a drop in water pressure.

An E119 error code will appear on your boiler system when the water pressure drops below 0.5 bar.


An E133 error code indicates an interrupted gas supply, an undetected flame, or an ignition failure.

An E133 error code can also signify that the condensate pipe has frozen.


An E168 error code on your boiler requires professional attention. It indicates a problem with the boiler but does not specify what the issue is.

As the boiler has detected an unknown issue, it is important that you shut it down until it can be checked. This safety precaution should protect your home until a Gas Safe-registered engineer can check.


An E110 error code indicates the flue system or primary water has overheated. This will typically result in the boiler shutting down.


An E160 error code on your boiler lets you know that there is an issue with the boiler's components.

As well as displaying an E160 error code, faulty gas boilers may also display the following error codes;


  • E28

  • E50

    If your boiler displays any of these error codes, you should contact a Gas Safe-registered engineer or the manufacturer.

    How to fix an E1 error on a boiler

    The different error codes allow you to determine whether you can resolve the issue or need a professional to fix faulty gas boilers.

    If you are having issues with your boiler, you should always check the error code prior to calling for help.

    The most common and easy-to-resolve error code is the E119. If you have low boiler pressure, the following steps should help you to resolve the issue.

    How to fix an E119 error on a boiler

    If your boiler shows an E119 error, the following steps will help you to resolve the issue.

    Step 1

    The first step should be to check the pressure gauge on your boiler. Your boiler pressure should be between 1 and 1.5 bar.

    An E119 will typically appear when the boiler pressure has dropped below 0.5 bar.

    Step 2

    After confirming the boiler pressure, you should turn off all towel rails and radiator bleeder valves.

    Step 3

    The next step is to locate the filling loop. Your user guide will advise you of the filling loop location.

    If the filling loop is unattached, you should fetch it. It will be like a pipe and have valves attached. Alternatively, it may be installed internally if you have a modern boiler.

    Step 4

    Internal and external filling loops should have their valves opened until the pressure reaches the desired level of 1.5 bar.

    After altering the pressure, the valves must be closed securely to minimise the risk of leaks.

    If your boiler has a detachable loop, remove it and store it securely.

    Resolving other E1 error codes

    Understanding when you can resolve an E1 error code can help to save you money. However, it is important when to know to get professional help, to ensure you and your family's safety.

    The following E1 error code advice will help to direct you with what action to take.

    How to fix an E133 error on a boiler

    If your boiler indicates an E133 error, you should ensure your gas supply is still on.

    Hold the selector switch for 5 seconds in the reset position if you have a gas supply.

    This should relight the boiler. If it fails to relight, contact the manufacturer or installer.

    If the E133 error displays during cold weather, it may be that the condensate pipe has frozen. If this is the case, pour warm water on the pipe to thaw it. Never pour boiling water on a frozen pipe.

    How to fix an E168 error on a boiler

    A 168 error is more difficult to determine. It could be something as simple as an issue with the electrical supply. Alternatively, there may be a more serious problem.

    Speaking with the manufacturer can help to diagnose issues. You should also consider speaking with a professional who will be able to safely check your boiler.

    How to fix an E110 error on a boiler

    If your boiler shows an E110 error, it will typically shut down. This safety precaution automatically kicks in if the flue system overheats.

    You can attempt to reset the boiler if this occurs. If the boiler does not reset, you should call an engineer.

    How to fix an E160 error on a boiler

    If your boiler shows an E160, E20, E28, or E50 error, there is an issue with a component within the boiler.

    You should contact your installer or the manufacturer with details of the error code. This will help to determine the issue and help you resolve the problem.

    PlumbNation plumbing and heating supplies

    Here at PlumbNation, we offer our customers an extensive range of plumbing supplies for the home. Whether you are looking for replacement boilers or radiators or need supplies for bathrooms or kitchens, we can help.

    If you're still having issues with a fault code, it might be time for a new boiler. At PlumbNation we stock a wide range including gas boilers, electric boilers, oil boilers, and LPG boilers. Explore our wide selection of products and helpful buying guides to ensure you buy the perfect products for your home.



    What happens if my boiler keeps losing pressure?

    If the boiler regularly loses pressure, there may be a more serious problem. Getting an engineer to look at the problem can help to resolve the issue. Alternatively, they may advise you to invest in a replacement boiler.

    Should I get a new boiler if an E1 error shows?

    An E1 error does not always mean there is a major issue with your boiler. However, you should still keep an eye on it.

    A recurring E1 error may be relatively simple to resolve, but it could mean there are deeper issues with your boiler. Always seek professional help if you are unsure or an error keeps occurring.

    How will fixing E1 fault codes impact my warranty?

    You should always check your warranty to ensure any repairs do not void a warranty. It may be that the manufacturer will require a Gas Safe-registered engineer to carry out any repairs on the boiler. Faulty components should only be replaced by a professional using approved parts.

    Will an E1 error automatically leave the display after being fixed?

    If an error code appears on your boiler, it will typically disappear from the screen after being resolved.

    If you are having boiler issues, you should note down any E1 fault code that shows. Do this in case it disappears from the screen before an engineer has the chance to check it.

    The more information you are able to provide to an engineer, the better chance they have of checking and resolving all the issues.

    Who should I contact regarding E1 fault codes?

    Baxi, Main, and Potterton boilers that display E1 fault codes can sometimes be resolved by homeowners.

    For peace of mind, you can speak with a Gas Safe engineer, your installer, or the boiler company's customer support team for advice.