Boiler Showing a Fault Code
The boiler has stopped and a letter-and-number code is showing on the display..
The boiler has stopped and a letter-and-number code is showing on the display.
What is actually going on
The boiler has stopped and a letter-and-number code is showing on the display.
The realistic causes, in order
A lockout after repeated failed ignition attempts, which the code will identify A sensor out of range — flow, return, outdoor or hot water — reported as a specific code A safety device operating, such as an overheat stat or condensate blockage detection
What we test on site
The code read against the manufacturer's own service manual, not a generic list The boiler's stored fault history, which shows whether this is a first event or a pattern The underlying condition the code points to, rather than just clearing it
Worth checking today if you have a fault code on the display
- Write down the exact code before resetting anything
- Reset once only — repeated resets hide the fault and can cause damage
- A code is the boiler protecting itself. Clearing it repeatedly without investigating is how a cheap repair becomes an expensive one.
Who does the work
- Gas Safe registered engineers — registration 554328
- Worcester Bosch accredited installer
- John The Plumb Ltd, company registration 10026483
Get a fault code on the display diagnosed properly
Codes make diagnosis quicker, which usually means less time on site and a clearer answer for you.
Questions we get asked
What causes a fault code on the display on a gas boiler?
A lockout after repeated failed ignition attempts, which the code will identify
What normally puts a fault code on the display right?
Codes make diagnosis quicker, which usually means less time on site and a clearer answer for you.
Is it safe to keep using the system with a fault code on the display?
A code is the boiler protecting itself. Clearing it repeatedly without investigating is how a cheap repair becomes an expensive one.