Worcester Bosch boiler
fault codes.
What the most common Worcester Bosch Greenstar fault codes mean, what you can safely check yourself, and when you need a Gas Safe engineer.
Before you start
- Never remove the boiler casing – only a Gas Safe engineer should work inside it
- Only reset the boiler as shown in your manual, and not more than once or twice
- If the same code keeps coming back, book a repair
Smell gas? Leave the property and call the National Gas Emergency Service on 0800 111 999.
The quick checks
- Pressure: the gauge should read between 1 and 1.5 bar when the boiler is cold. Below 1 bar it needs topping up
- Gas: do your hob and other gas appliances work? Is there credit on a prepayment meter?
- Condensate pipe: in freezing weather, is the outside plastic pipe frozen? Only thaw it at ground level, with warm (not boiling) water
- Power: is the boiler’s fused spur switched on?
Common Worcester Bosch fault codes
EA (often shown with 227) – The boiler could not light.
Worcester Bosch lists three causes: no gas supply or low gas pressure, a blocked condensate outlet (often frozen in cold weather), or a blocked or damaged flue. Check your other gas appliances and prepayment credit, check the condensate pipe outside if it is safe to reach, and look for anything blocking the flue. Then press reset once. If it comes back, book a repair.
Low pressure (pressure gauge below 1 bar, or LoPr on newer models) – Not enough water pressure in the heating system.
Top up to between 1 and 1.5 bar with the filling link, as shown in your user instructions. On newer models the boiler stops working at 0.2 bar or below. If you keep having to top up, there may be a leak – book a repair.
H13 – Service interval reached – not a fault.
The boiler is reminding you it is due a service. Book a Worcester Bosch boiler service.
2980 (newest models) – A safety-related fault.
Worcester Bosch says to contact a qualified heating engineer straight away and not to try to fix it yourself. Heating and hot water stay off until it is repaired.
Any other code – Shown as letters with a three-digit number underneath.
Note both the letters and the number (for example EA and 227) and press reset once. Some codes cannot be cleared with a reset and need an engineer. Book a repair and tell us the full code.
Frozen condensate pipe
In cold weather, a gurgling noise and an EA code usually mean the condensate pipe outside has frozen. Worcester Bosch advises pouring warm (not boiling) water along the frozen part, or holding a hot water bottle on it, then resetting the boiler. Only do this at ground level, and watch for ice on paths.
If it keeps freezing, the pipe can be rerouted inside, insulated or made larger. See our frozen condensate pipe guide.
Need a repair?
A diagnostic visit is £92.50 for the first 45 minutes. Once the fault is found, we give you a fixed price for the repair before any work goes ahead – often from photos or a short video of the boiler and its display.
Boiler keeps breaking down?
If your boiler is old and the faults keep coming back, a replacement may cost less than you think. See fixed, fully installed prices with our online boiler price.
About this list
Codes and meanings vary between Worcester Bosch models, so check your boiler’s user instructions. This guide is based on Worcester Bosch’s published user instructions for its Greenstar boilers and its frozen condensate advice. Worcester Bosch’s own information is at worcester-bosch.co.uk.