That error code your boiler is showing is not a random string of letters and numbers — it's telling you exactly what's gone wrong. Understanding that code can help you explain the problem clearly when speaking to a heating engineer and speed up the boiler fix process.
Below, we're breaking down some of the most common boiler fault codes and what they usually mean, so let you know whether it's something simple that you can reset yourself or a more serious issue that needs a Gas Safe engineer.
- Vaillant error code F28
This means your boiler isn't igniting. Check that the gas supply is on and the meter isn't faulty. If your model has a pilot light, make sure it's lit. If those look fine and the error stays, call a Gas Safe engineer to inspect the ignition system or burner. You'll need a professional boiler fix.
- Worcester error code C6
This points to a fan or air supply issue. Look to see if the fan is running and check that the air intake isn't blocked. Don't try to fix fan or airflow problems yourself — book a qualified technician for the boiler fix.
- Ideal error code L6
This usually means the temperature sensor is faulty or the wiring is damaged. Don't try to repair this yourself. Call a heating engineer to check the sensor and wiring and complete the boiler fix safely.
- Ideal error code L4
The flow thermistor has a fault. Try resetting the boiler once, but if the error returns or it won't reset, stop there. A heating engineer should inspect the part and complete the boiler fix if needed.
- Worcester Bosch Classic Combi error code A1
Your boiler may have lost pressure, or the pump may have stopped working. Don't try to fix this yourself. Call a Gas Safe engineer to diagnose the cause and carry out any repairs or part replacements.
- Vaillant error code F13
The cylinder temperature sensor has likely short-circuited. This is either a wiring issue or a faulty sensor. It involves electrical work, so don't DIY this. Contact a professional for a safe and accurate boiler fix.
- Ideal error code LC
You've reset the boiler too often in a short time. Turn it off completely, wait a few minutes, then turn it back on. If the code returns, there's an underlying problem. Get a heating specialist to investigate.
If your boiler is showing any of these error codes, contact WPJ Heating at 020 4572 9519, and they'll send out one of their Gas Safe registered engineers to inspect the issue. The WPJ Heating team knows boilers inside and out, and they're quick to identify what's causing a fault and carry out a safe, lasting boiler repair in Clapham.
About the Author:
In 2002, Will Hawksley and PJ Luard established WPJ Heating with the ambition of attaining the foremost position among heating companies in London. The two individuals deliberated on the complexities of plumbing and boilers before deciding to collaborate. At present, WPJ Heating has expanded its staff to 26 members. Their cadre of skilled professionals encompasses gas engineers, plumbers, a specialised team for drainage and pressure jetting, versatile bathroom fitters, electricians, and decorators.
