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What Does E1 Mean On A Boiler?


So, your boiler has suddenly flashed the E1 Error Code, and you’re wondering, “What is happening to my poor boiler?” There’s no need to worry. Fortunately, the E1 Error Code isn’t critical. It’s among the fairly common errors that pop on boilers. With our help, you can even fix it without calling a certified Gas Safe engineer.

Most of the time, the E1 Error Code means that the boiler is running low on pressure. All you have to do is repressurise your boiler, and everything will go back to normal.

That being said, the Error Code might also hint that something else is wrong with your boiler. To help specify the problem, you need to pay attention to the digits that follow “E1.” For example, if your boiler shows the E119 Error Code, you can be sure that low pressure is the only problem.

Below is a table displaying all the specific E1 Error Codes and their possible causes. Remember, if low pressure isn’t the issue, then you must call a Gas Safe engineer. The law doesn’t authorise you to fix faulty gas boilers. It’s too dangerous.

E119 Is displayed when the boiler’s water pressure falls below 0.5 bar. You can repressurise the boiler. Follow the steps down below.
E20, E28, E50, and E160 Faulty components. Take note of the displayed Error Code and immediately contact a certified Gas Safe engineer.
E110 Displayed overheat of the primary water or flue system has occurred. Turn the selector switch to the reset position and hold it for at least 5 seconds. If the boiler does not relight, or the code is displayed regularly contact your installer for the same.







This indicates that the gas supply has been interrupted, ignition has failed or the flame has not been detected.







Can also display in the winter if the condensate pipe of your boiler has frozen.

Ensure that the gas supply has not been turned off, and turn the selector switch to the reset position and hold for at least 5 seconds. If the boiler does not relight, or the code is still displayed, contact your installer.



The boiler will switch off to protect itself.

E168 Could mean that your boiler has detected a problem but can’t work out exactly what it is.  This could be because the boiler has been reset after developing a fault or because there has been an external issue, such as a fault with the electrical supply. The boiler might have been displaying a different error code before resetting, so it is useful to make a note of any error codes you see as this will help your installer identify the issue.

How to Repressurise your boiler

First, before you touch anything, we’d like you to locate your boiler’s pressure gauge and confirm the pressure reading. Ideally, you want the boiler pressure to be around 1 to 1.5 bar. If your boiler is suffering from low pressure, expect it to be below 1 bar. In the case scenario, the pressure might have dropped to somewhere below 0.5 bar.

We advise you to use the user’s guide to locate your boiler’s pressure gauge.

Step 1

Make sure that all radiator bleeder valves and towel rails are turned off.

Step 2

Most boilers have external filling loops. Yours might already be attached to your boiler. We advise you to consult your user’s guide or do some internet research.

If it’s unattached, fetch your filling loop. Chances are your engineer handed you a pipe-like tool with valves. In case you don’t have one, they are available for purchase at your convenience hardware store.

Some modern boilers come with in-built filling loops. To find it, we are once again advising you to consult your user’s guide.

Step 3

For boilers with external filling loops, open the valves as you read the pressure gauge. Keep the valves open until the pressure reaches 1.5 bar. Close the valves.

If the filling loop is detachable, you’re advised to remove it and store it in a safe place.

For boilers with inbuilt filling loops, the process is more or less the same. Open the valve until the pressure reaches 1.5 bar, then close.

In both cases, make sure you completely close the filling loops to prevent leaks.

Is your boiler pressure falling regularly?

Chances are, your boiler is leaking. Don’t attempt to open the boiler unit by yourself. It’s not safe. Quickly shut down the unit and call a Gas Safe engineer. The task at hand is sacred and dangerous.

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