Help Guide
Boiler Fault Codes
Explained
Your boiler is showing an error code. Here is what the most common codes mean — and whether you need an engineer.
Modern boilers display error codes to help diagnose faults. Below are the most common codes for popular boiler brands. If your fault code is not listed, call us on 07733 019491 and we can advise.
Worcester Bosch Fault Codes
| Code | Meaning | Action |
|---|---|---|
| EA | Ignition lockout — boiler failed to ignite | Try reset. If repeats, call engineer |
| A7 | Low water pressure | Repressurise to 1–1.5 bar. If repeats, internal leak suspected |
| E9 | Overheat safety cutout | Call engineer — do not keep resetting |
| CE | Fan or air pressure fault | Call engineer |
Vaillant Fault Codes
| Code | Meaning | Action |
|---|---|---|
| F.22 | Low water pressure | Repressurise system |
| F.28 / F.29 | Ignition failure | Reset once. If repeats, call engineer |
| F.75 | Pressure sensor fault | Call engineer |
| F.62 | Gas valve fault | Call engineer immediately |
Ideal Boiler Fault Codes
| Code | Meaning | Action |
|---|---|---|
| L2 | Ignition lockout | Reset — if repeats, call engineer |
| F1 | No gas or ignition failure | Check gas supply, then call engineer |
| F2 | Flame loss during operation | Call engineer |
Baxi Fault Codes
| Code | Meaning | Action |
|---|---|---|
| E168 | Gas or ignition fault | Check supply, reset, call if repeats |
| E119 | Low water pressure | Repressurise to 1–1.5 bar |
| E160 | Fan fault | Call engineer |
How to Repressurise Your Boiler
Many faults showing low pressure can be fixed by repressurising. Here is how:
- Turn the boiler off and let it cool for 10–15 minutes
- Locate the filling loop — usually a silver braided hose underneath the boiler
- Slowly open both valves on the filling loop until the pressure gauge reads 1–1.5 bar
- Close both valves
- Restart the boiler
If pressure keeps dropping, there is likely an internal leak — call us for a diagnosis.
Not sure about your fault code? Call us on 07733 019491 — tell us your boiler brand and the code displayed and we can advise whether you need an engineer out.
Need Help? Call Us Now.
Same-day response. Gas Safe registered. All of Surrey.