If you are wondering what your Potterton boiler E1 error code means and how to fix it, don’t worry—we’ve got you covered in our guide to resolving this type of boiler issue.
Most boilers come with an in-built error code to alert homeowners when something goes wrong. With a manual, homeowners can understand what each fault code means and look for possible solutions.
Even though it is frustrating to see an error code appear on your boiler, the E1 code is fairly common when it comes to issues with Potterton boilers, and normally the problem isn’t too serious and straightforward to solve. An E1 code typically means your boiler has low pressure, which leads it to lock you out and not work properly.
In this guide, we’ll explain the common reasons behind the E1 fault code, how it affects your boiler, and the quickest way to resolve the issue.
If your boiler is old and unreliable, and repair costs are piling up, simply answer a few questions to see if you are eligible for a government-backed scheme free funding to replace your boiler.
Understanding the Potterton Boiler E1 Error Code
The E1 error code is a common boiler issue and usually isn’t a cause for concern. It generally indicates low water pressure, which can cause the boiler to shut down as a safety measure.
If you see the E1 code, the solution might be as simple as increasing the boiler’s pressure — a straightforward process that we’ll explain below. However, the E1 code can also signal other issues that may require a gas-safe engineer’s expertise.
The digits following “E1” can provide more insight into the problem:
E119: This code points to low water pressure, the most common cause. Repressurising the system usually fixes it.
E133: This indicates a gas supply issue. Ensure the gas supply is on and reset the system. If the problem continues, contact your installer.
E168: This code suggests the boiler has detected an issue but can’t identify the source. Further inspection may be needed.
When you see the E1 code, it’s natural to worry, but in most cases, it just means low pressure—a problem you can often fix on your own. If low pressure isn’t the cause, or if you’re unsure, it’s best to consult a certified Gas Safe engineer.
Below, we’ll go into detail about the E1 fault code, its causes, and solutions, so you can accurately diagnose and resolve the issue.
Steps to Fix the E1 Fault Code
- When your boiler displays the E1 code, it means there’s been a significant drop in system pressure. The fix is to repressurise the boiler.
- When the boiler is off, the pressure gauge should read around 1 bar, which is in the green zone.
- When in use (heating water or providing heat), the pressure will rise slightly and then drop back down.
- However, if the E1 code appears, the pressure will be low, shown on the gauge as being in the lower red zone.
- Repressurising the boiler is a simple task, so it’s good to familiarise yourself with the process.
- However, if the pressure keeps dropping after you’ve re-pressurised the system, this could indicate a leak or another issue in your boiler that requires attention from a gas-safe engineer.
If the problem is low pressure, here’s how to repressurise your boiler.
How to Repressurise A Potterton Boiler
As boilers age, it’s normal to need to repressurise them occasionally, especially if the E119 code appears. The first step is to check the pressure gauge. Normally, boiler pressure should be between 1 and 1.5 bar. If the gauge reads below 1 bar, you likely have low pressure.
- Turn off all radiator bleeder valves and towel rails.
- If your boiler has an external filling loop, attach it to the boiler.
- Open the valves to increase the boiler’s pressure through the filling loop. Watch the pressure gauge as you do this.
- Once the pressure is within the normal range, close the valves and detach the filling loop.
- Ensure the valves and filling loop are fully closed to prevent leaks.
Boiler Continues to Drop Pressure After Repressurising?
If your boiler continues to lose pressure quickly, it may indicate a more serious problem that needs addressing, possibly requiring a boiler replacement. There might be some other factors at play and these include:
Faulty Diverter Valve
If your Potterton boiler isn’t providing hot water, a faulty diverter valve might be the issue. However, it could also be due to a faulty Printed Circuit Board (PCB). To accurately diagnose the problem, a gas-safe engineer should inspect your boiler.
Frozen Condensate Pipe
The condensate pipe carries acidic water from the boiler to your external drain. If it’s frozen, your Potterton boiler will lock out and display the E133 code.
Thawing a frozen condensate pipe is fairly simple. However, if you’re not confident in doing it yourself, a local Gas Safe engineer can help.
Uneven Radiator Heating?
If your radiators aren’t heating evenly or a particular radiator isn’t getting warm enough, there may be excess air in your heating system. To release this air, you’ll need to bleed your radiators. This is a simple DIY task; you’ll need a valve key, a bucket, and some sheets to catch any water.
With your heating turned off and cool, turn the valve using the key until you hear air hissing out. When the hissing stops, close the valve and move to the next radiator.
After bleeding all your radiators, you’ll need to repressurise your Potterton boiler. If the problem persists, cold radiators could be caused by sludge buildup or another issue.
Boiler Lockout?
If your boiler keeps shutting off or “locking out” without showing a clear error code, it could be due to several underlying issues, such as a faulty heat exchanger, thermostat, or PCB.
Boilers generally shut down for two main reasons: to prevent further damage to the system or to protect the safety of those in the household.
It’s important not to repeatedly restart the boiler before identifying and resolving the issue. Doing so could lead to further damage or safety risks.
If your Potterton boiler keeps turning off without any obvious cause or error code, it’s time to seek professional help. A registered Gas Safe Engineer can diagnose and fix the problem.
Common Potterton Boiler Error Codes
Fault Code Possible Cause
E09 Gas valve wiring issue
E10 Outdoor sensor error
E15 Gas valve connection problem
E20 Central heating thermistor sensor issue
E28 Flue thermistor problem
E40 Central heating return thermistor issue
E50 Hot water sensor problem
E53 Flue obstruction
E55 Calibration issue
E78 Water pressure sensor issue
E92 Combustion test alarm
E109 Poor circulation
E110 Boiler overheat tripped
E117 System pressure too high
E118 System pressure low
E119 System pressure low
E125 Primary water circulation issue
E128 Loss of flame
E129 Loss of flame
E130 Flue thermostat sensor tripped (lockout)
E131 Flue overheat lockout
E133 Ignition fault
E135 Internal error
E151 PCB fault
E152 PCB fault
E154 Primary flow issue
E160 Fan fault
E161 Fan fault
E164 Hot water sensor error
E167 PCB fault
E168 PCB lockout
E193 Circulation issue
E270 Dry fire
E317 Wrong power supply
E321 Hot water thermistor fault
E384 Flame detected when the gas valve is off
E385 Low voltage issue
Boiler Beyond Economical Repair, What Next?
It’s possible you may need a replacement for your boiler. The cost may be a real cause of concern, but there is also the possibility you may be eligible for free ECO grant funding.
The Energy Company Obligation (ECO) is a UK government initiative aimed at helping low-income households improve their home’s energy efficiency. Starting in April 2022, ECO will run throughout 2026. Its primary goals are to help those considered to be in fuel poverty with energy efficiency improvements that will reduce energy bills.
Funded by energy companies, this initiative plays a crucial role in reducing the nation’s carbon footprint. A key feature of the ECO scheme is the provision of free boiler grants for eligible low-income households. Upgrading to a new, more energy-efficient boiler can significantly enhance a home’s energy efficiency.
Homeowners (and some tenants) may be eligible for full and partial and complete grants. Click here to check your eligibility status!