Encountering error codes on your Worcester Bosch boiler can be concerning, especially during the colder months. Understanding these Worcester Bosch boiler error codes can help you determine whether it’s a simple fix you can handle yourself or if you need professional assistance. As local heating engineers serving Wiltshire homes for many years, we’ve encountered virtually all the fault codes that these reliable boilers can display.
In this guide, we’ll explain the most common error codes, what they mean, and what you can do about them.
EA Error Code – Flame Recognition Issue
The EA code typically indicates that your boiler is having trouble detecting a flame. This could be caused by:
- Gas supply issues
- Faulty flame sensor
- Ignition problems
What you can try: Test another gas appliance to see if your gas supply is working. Also, ensure your boiler has been on recently, as the EA code can sometimes appear after periods of inactivity. If other gas appliances are working, try resetting your boiler by turning it off, waiting 30 seconds, and turning it back on.
If the code persists, call a professional heating engineer. It may indicate an issue with the internal components.
E9 Error Code – Flame Recognition Safety Issue
This error is similar to EA but potentially more serious because it involves safety circuits. Your boiler has detected a problem with the flame recognition system.
What you can try: This isn’t typically something you can fix on your own. The safety mechanisms in Worcester Bosch boilers are designed to shut down the system when they detect potentially unsafe conditions. You’ll need a Gas Safe registered engineer to diagnose and resolve this issue.
H07 Error Code – Low System Pressure
One of the most common issues we encounter when repairing Worcester boilers across Trowbridge and Melksham is the H07 error, which indicates low water pressure in your heating system.
What you can try: This is often something you can fix yourself:
- Locate the filling loop on your boiler (usually a silver flexible hose with two valves)
- Ensure both valves are initially closed
- Open both valves to allow water into the system
- Watch the pressure gauge until it reaches between 1 and 1.5 bar
- Close both valves once the correct pressure is reached
If your system frequently loses pressure, this could indicate a leak somewhere in your heating system, and you’ll need a professional assessment.
E4/E5 Error Code – Boiler Safety Thermostat Activated
These codes appear when your boiler has overheated and the safety thermostat has activated to prevent damage.
What you can try: First, check for airlock issues or if some radiators aren’t heating properly. You might need to bleed your radiators to remove trapped air. Also, ensure your heating controls are set correctly.
If the error persists after the boiler has cooled and been reset, it could indicate a circulation problem, pump failure, or thermostat issue that requires professional attention.
CE/C2 Error Code – Communication Fault
This indicates a communication error between the boiler and its controls. We often see this in homes across Westbury and Frome, particularly with older Worcester models.
What you can try: Check if your room thermostat batteries need replacing, as this is often the simplest fix. Try resetting both the boiler and the thermostat. If the issue continues, you may have a wiring problem or a fault with the control board.
A1/A2/A3 Error Codes – Water Flow Problems
These codes typically relate to the pump and water circulation issues within your heating system.
What you can try: Ensure all radiator valves are open. Listen for the pump running when the heating is on – you should hear a gentle humming. If there’s no sound or unusual noises, the pump may be stuck or faulty.
Sometimes, tapping the pump housing gently can free a stuck pump, but this is just a temporary fix, and you’ll likely need a heating engineer to investigate further.
F1/F2/F3 Error Codes – PCB Faults
These error codes typically indicate an issue with the boiler’s main circuit board (PCB) or its sensors. Unfortunately, these usually require professional diagnosis and repair.
What you can try: The only DIY approach here is to try a reset. Turn off the boiler at the mains, wait a minute, then turn it back on. If the error persists, you’ll need expert help as PCB issues can be complex.
E2/E3 Error Codes – Sensor Failures
These codes indicate that temperature sensors within the boiler are providing faulty readings.
What you can try: These sensors are internal components that require professional replacement. While waiting for an engineer, you can try a reset, but this will likely only provide temporary relief if successful at all.
When to Call a Professional
While some Worcester Bosch boiler fault codes can be resolved with simple fixes, many require professional attention. You should contact a Gas Safe registered engineer if:
- The error code persists after you’ve tried the relevant simple fixes
- Any error code relates to gas supply or flame issues (such as EA or E9)
- You smell gas or notice any sooting around the boiler
- Your boiler makes unusual noises or is showing multiple error codes
- The F1/F2/F3 PCB fault codes appear
- You’re unsure about any aspect of troubleshooting
Preventing Future Error Codes
The best way to avoid encountering fault codes is through regular maintenance. Annual servicing by a qualified heating engineer can identify potential issues before they cause a breakdown and ensure your boiler operates efficiently.
As we explain in our guide to boiler efficiency, preventative maintenance reduces the likelihood of error codes, lowers energy bills, and extends the lifespan of your boiler.
Expert Worcester Bosch Boiler Repairs in Wiltshire
If you’re facing persistent error codes on your Worcester Bosch boiler and need expert assistance, our team of Gas Safe registered heating engineers is here to help. We specialise in diagnosing and repairing all models of Worcester Bosch boilers across Trowbridge, Melksham, Westbury, Frome, Warminster and Chippenham.
With our same-day boiler repair service, we can quickly resolve your heating problems and get your home warm again. Don’t let Worcester Bosch boiler fault codes leave you in the cold – contact A N Heating Ltd today on 01225 708 562 or email info@anheating.co.uk to arrange a prompt visit from one of our experienced heating engineers.
