Boiler error codes are clues that something is not right. Each code means a different problem. Some tell you about pressure issues, others talk about the flue system or indicate that the boiler can’t light up properly.
Look at your boiler’s display and you’ll see these codes when there’s trouble. They help you figure out what to fix without guessing.
Now let’s dig into what E1 specifically means for your boiler and how to address it.

Key Takeaways
- The E1 error code on a boiler signals low pressure or an ignition failure, which stops the heating system from working properly.
- You can often fix the E1 error by repressurising your boiler system using the filling loop to reach around 1.5 bar pressure.
- Different variants of the E1 error like E119, or F1 each have specific meanings and fixes, such as checking water pressure or addressing gas supply issues.
- If simple fixes do not work, it’s best to call a Gas Safe registered engineer for help with complicated problems like sensor faults or repeated errors.
- Regular servicing by a certified professional is important to prevent future issues and maintain a safe and functioning boiler.
What Does E1 Mean on a Boiler?
The E1 error code on a boiler indicates an ignition failure, preventing the boiler from heating water for your central heating system. There are also variants of the E1 error code, such as F1, which may indicate different issues with your boiler.
Causes of E1 Error Code
Low boiler pressure often triggers the E1 error code. This could mean there is a water leak in the system, or maybe air has got into the heating and cooling pipes. Over time, wear and tear on your central heating system can lead to these issues.
Sometimes, if you’ve recently bled your radiators using radiator bleeder valves, it might cause low pressure too.

Other reasons for an E1 error might be related to the boiler’s internal workings. Faulty pressure sensors can give wrong readings, making your boiler think there’s a pressure issue when there isn’t one.
In cold weather, the condensate pipe could freeze and block, leading to errors as well. If your boiler has trouble with ignition failure or gas supply issues, it may display variants of E1 like E133 or others that require attention from professionals such as a Gas Safe registered engineer.
Variants of E1 Error Codes, Including F1
E1 error codes on your boiler can show up in different ways. Some boilers flash ‘E119’ when they run into trouble – that usually means the pressure is too low. You might also see ‘E133’, which points to an ignition problem or a stop in the gas supply.
Other times, ‘F1’ pops up, and this signals a fault with the heating system’s water flue or overheating parts.
These codes tell you there’s something not quite right with your boiler. They hint at what’s happening inside: maybe there’s leakage, the heat exchanger isn’t working well, or you need more water pressure for things to run smoothly.
If ‘E1’ shows on your boiler pressure gauge, checking these issues could help fix it before we move on to how to tackle an E1 error code directly.
How to Fix E1 Error Code on a Boiler
To fix the E1 error code on a boiler, you can try repressurising the system using the filling loop. If you encounter other variants of the E1 error code, such as F1, there are specific steps to resolve them as well.
Repressurising System
Seeing the E1 error code on your boiler can be worrying. You might have to repressurise your system using the boiler filling loop.
- Locate the boiler filling loop, often found below the unit.
- Check that the boiler is turned off and cool before touching any parts.
- Open both valves on the loop slowly to let water into the system.
- Watch the pressure gauge; it should rise to about 1.5 bar.
- Stop adding water when it hits the correct pressure level.

- Securely close both valves on the filling loop after repressurisation.
- Switch on your boiler and check if the E1 error code has cleared.
- If issues persist, seek help from a Gas Safe engineer as annual servicing could prevent these problems.
Resolving Other E1 Error Codes
Boiler error codes can be confusing. Different E1 errors need specific solutions.
- Check the boiler manual. Each E1 variant has a unique fix listed in the manual.
- For E119, it usually means low water pressure. Increase pressure using the filling loop.
- An E133 error code signals a gas supply problem. Ensure gas valves are fully open.
- Reset the boiler if you see E168. This indicates an electrical issue that a reset may clear.
- If E110 appears, it’s an overheating problem. Let the boiler cool down before resetting.
- The E160 code points to a fan fault. Turn off the boiler and call a technician.
- Addressing an E20 or E28 involves sensor checks. Replace any faulty sensors.
- For complicated problems like an E50 error, get help from a registered engineer.
Conclusion
Understanding what E1 means in your boiler helps you keep the hot water flowing. Simple fixes like repressurising can often solve the problem. Remember to check for different E1 error variants before calling a pro.
Annual checks by a Gas Safe engineer are key to a healthy boiler. Have you checked your boiler’s pressure lately? Keep warm and carry on with these easy tips!
If you also encounter the F1 error code, please read our detailed guide on what F1 means on a boiler for more information.