If your boiler is displaying an E1 error code, don’t panic. It’s one of the most common and fixable faults in UK heating systems. This guide is for UK homeowners, landlords, and commercial property owners who want to understand what the E1 boiler error means, how to resolve it, and when to call in a professional.
What Is the E1 Boiler Error Code?
The E1 boiler error typically signals low water pressure, which can cause your boiler to shut down as a safety precaution. It’s often a straightforward fix, but ignoring it can lead to bigger issues like system inefficiency, cold radiators, or even long-term damage.
Common E1 Variants and Their Meanings
- E119: Low water pressure (below 0.5 bar).
- E133: Ignition failure or gas supply issue.
- E168: General fault. It usually means the boiler cannot identify the specific issue.
- E110: Overheating detected in the system.
- E160, E50, E28, E20: Component faults within the boiler.
Understanding these codes can help you diagnose the issue more accurately and decide whether it’s a DIY fix or time to call a professional.
If a professional determines that you require a new boiler, you can get a free boiler installation quote from Future Heat for homes & commercial properties based in Newcastle & the North East of England.
What Causes the E1 Boiler Error?
Understanding the root cause of an E1 boiler error is crucial for resolving the issue quickly and effectively. While the error commonly relates to low water pressure, there are several other potential triggers depending on your boiler make and model.
Identifying the specific cause will help you determine whether a simple DIY fix is possible or if professional intervention is required.
1. Low Water Pressure
The most common cause of the E1 error is low water pressure in the boiler system. This can occur due to:
- Leaks in the system.
- Bleeding radiators without repressurising.
- A faulty pressure relief valve.
Boilers typically operate between 1.0 and 1.5 bar. If the pressure drops below this range, the boiler may shut down to prevent damage.
Not every boiler brand uses E1 as a way to show there is low water pressure. For example, the Vokera boiler error code for low pressure is A04.
2. Gas Supply Issues
An E133 code indicates a problem with the gas supply or ignition. This could be due to:
- A closed gas valve.
- Issues with the gas meter.
- A frozen condensate pipe in cold weather.
3. Component Failures
Codes like E160 or E20 suggest internal component failures, such as:
- Faulty sensors.
- Malfunctioning fans.
- Issues with the printed circuit board (PCB).
These issues typically require professional diagnosis and repair.
How to Fix the E1 Boiler Error Code: Step By Step
Before you call out a heating engineer, there are a few simple troubleshooting steps you can take to resolve the E1 error code yourself.
Many of these tasks, like checking boiler pressure and resetting the system can be performed safely by most property owners, provided the instructions are followed carefully. However, if you’re unsure or the problem recurs, always consult a Gas Safe registered professional.
Step 1: Check the Pressure Gauge
Locate the pressure gauge on your boiler. If it’s below 1.0 bar, you’ll need to repressurise the system.
Step 2: Repressurise the Boiler
- Turn off the boiler and allow it to cool.
- Locate the filling loop (a silver, flexible hose beneath the boiler).
- Open both valves on the filling loop to allow water into the system.
- Watch the pressure gauge rise to 1.5 bar, then close both valves.
- Turn the boiler back on and check if the error code has cleared.
For detailed instructions, refer to your boiler’s user manual or consult a professional.
Step 3: Reset the Boiler
After repressurising, you may need to reset the boiler. This is usually done by pressing and holding the reset button for a few seconds. Again, consult your boiler’s manual for specific instructions.
When to Call a Professional
If the E1 error persists after you’ve attempted to repressurise and reset the boiler, it’s time to call a Gas Safe registered engineer. Persistent issues may indicate:
- Leaks in the system.
- Faulty components.
- Gas supply problems.
Professional servicing ensures safety and compliance with UK regulations.
Tips for Preventing Boiler E1 Errors
- Regular Maintenance: Schedule annual boiler servicing to catch issues early.
- Monitor Pressure: Check the pressure gauge monthly.
- Bleed Radiators Carefully: Always repressurise after bleeding radiators.
- Insulate Pipes: Prevent frozen condensate pipes in winter.
Frequently Asked Questions (FAQs)
Yes. Running a boiler with low pressure can damage internal components and reduce efficiency. Always address the error promptly to avoid costly repairs.
Not necessarily. Most E1 faults are fixable. Only recurring or severe issues, like faulty sensors or PCBs, might suggest it’s time to consider a boiler replacement. If you’re unsure whether your boiler is nearing the end of its life, the first step is to find out how old your boiler is to know whether you need a replacement or not.
It can. Bleeding radiators releases air but also drops water pressure, which may trigger the E1 code if you don’t top up the system afterwards.
If the pressure reads low but the system feels hot and works normally, the gauge may be stuck or broken. A professional can test and replace it if needed.
Yes, if your boiler has a fault, it’s usually best to turn it off until it can be inspected by a qualified heating engineer. Continuing to operate a faulty boiler could worsen the issue or pose a safety risk, especially if there are signs of leaking water, unusual smells, or strange noises. Most modern boilers will display an error code when there’s a problem—check your boiler’s manual or contact a Gas Safe registered engineer to diagnose the fault safely.
In Summary
Whether you’re a homeowner trying to reduce heating disruptions, a landlord aiming to stay compliant with EPC regulations, or a commercial property manager focused on operational efficiency, understanding boiler fault codes is essential for long-term system health and cost savings.
The E1 fault is one of the most common alerts you’ll encounter, and thankfully, it’s usually easy to diagnose and fix, especially when related to low pressure. Staying proactive with regular maintenance, pressure checks, and timely servicing can prevent small issues from turning into costly repairs.
If your boiler continues to show fault codes or fails to restart after basic troubleshooting, it’s best to contact a Gas Safe registered engineer for professional support.
Myles Robinson is a seasoned expert in the boiler and home improvement industry, with over a decade of experience. He is deeply committed to environmental sustainability, actively promoting energy-efficient heating solutions to help households reduce their carbon footprint. By combining industry expertise with a dedication to environmental responsibility, Myles continues to lead efforts in transforming home heating practices towards a more sustainable future.
