Worcester Bosch boilers show a fault as two parts: a short display code and a number — for example EA 227. The number is the most useful part, because it pins down the exact fault. Newer boilers such as the Greenstar 8000 range use a number and a letter instead, for example 1017 W. Codes differ between models, so always check the user manual for your boiler.
📊 Common Worcester Bosch Codes
| Code | What it means | What to do |
|---|---|---|
| EA 227 | No flame detected when the boiler tried to light | ✅ Check gas supply and condensate pipe, reset once |
| EA 229 | Flame lost while the boiler was running | ✅ Check the condensate pipe in cold weather, reset once |
| E9 224 | Overheat — safety thermostat or limiter has tripped | Check pressure is 1–1.5 bar, reset once, then call an engineer |
| A1 281 | Pump stuck, or running with air or too little water | ✅ Check pressure, then call an engineer |
| C6 215 | Fan running too fast (Si, CDi Compact, Greenstar i) | Call an engineer |
| E5 218 | Flow temperature too high (Si, CDi Compact) | Check radiator valves are open, then call an engineer |
| D5 | Condensate problem — blocked pipe, or condensate pump fault on Highflow models | ✅ Check the condensate pipe, then call an engineer |
| 1017 W, 2971 B | Water pressure too low (Greenstar 8000) | ✅ Top up to 1–1.5 bar |
| CE 207, H07 | Water pressure too low (some models) | ✅ Top up to 1–1.5 bar |
| H + number | Service reminder — the boiler keeps working | Book a service or engineer visit |
Not listed, or your boiler shows something slightly different? Check the user manual, or call us with the full code and the model name from the front of the boiler.
🔥 EA 227 and EA 229 — Flame Faults
EA 227 means the boiler tried to light but no flame was detected. EA 229 means it lit but the flame went out while running. In cold weather, a frozen condensate pipe is one of the most common causes of both.
- Do your other gas appliances, such as the hob, work? If not, the problem is the gas supply, not the boiler.
- On a prepayment meter? Check it has credit.
- Freezing outside? Check the condensate pipe (see below).
- Then reset once, using the reset button or the reset option on the display.
If the code comes back, stop resetting and call a Gas Safe engineer. The cause is usually a part such as the ignition electrode, flame sensor or gas valve.
💧 Low Water Pressure
Worcester boilers show low pressure in different ways depending on the model (see the table). The gauge should normally read about 1–1.5 bar when the heating is cold.
- Turn the boiler off and let the system cool.
- Top up with the filling loop or built-in filling key, following the steps in your boiler’s user manual, until the gauge reads 1–1.5 bar.
- Close the filling valves fully, then turn the boiler back on.
If the pressure keeps dropping, there’s a leak or a faulty part and it needs an engineer. More help: boiler pressure low.
❄️ Frozen Condensate Pipe
The plastic pipe that carries water from the boiler to a drain outside can freeze in a cold snap and lock the boiler out.
- Find the pipe where it leaves the house and look for ice, especially at bends and the open end.
- Warm it with a hot water bottle or warm cloth, or pour warm water over it. Never use boiling water — it can crack the pipe.
- Only thaw pipework you can reach safely from the ground.
- Once it’s clear, reset the boiler once. If it still won’t light, call a Gas Safe engineer.
How to stop it happening again: frozen condensate pipe guide.
💷 Worcester Bosch Repair Costs in London
| Repair | Rough price |
|---|---|
| Low pressure or condensate fix | £80 – £150 |
| Sensor, thermostat or ignition part | £100 – £250 |
| Diverter valve, fan or pump | £150 – £350 |
| Gas valve or circuit board (PCB) | £200 – £550 |
| Heat exchanger | £300 – £700 |
Rough guide for London, parts and labour. The exact price depends on your boiler and the part. Our engineer gives you a fixed price after seeing the boiler, before any work starts. No VAT added.
Boiler still under its manufacturer’s guarantee? Contact Worcester Bosch first, as they deal with guarantee repairs. Old boiler that keeps breaking down? See repair or replace your boiler.
🏆 Worcester Bosch Repairs with FE Maintenance
- Gas Safe registered, fully insured — every engineer works directly for FE Maintenance, no subcontractors
- Fixed price agreed before any work starts, no VAT added
- Emergency call-outs Monday to Friday, 8am–8pm, from £99 — see emergency gas engineer
- Yearly boiler service from £80 to catch faults early
We cover North, West and Central London, plus Potters Bar and Hatfield. Call 020 8445 1303 or ask for a quote.
General guidance, cross-checked against several published Worcester Bosch fault code lists, as of October 2026. Codes vary between models — your boiler’s user manual is the final word.
Frequently Asked Questions
Worcester Bosch Still Showing a Fault?
A Gas Safe engineer from FE Maintenance can find the cause and fix it, with a fixed price agreed before any work starts.
info@femaintenance.com · 171 Crescent Road, Barnet EN4 9RN