Worcester Bosch Boiler Error codes / Fault codes
Worcester Bosch boilers are very popular and considered to be the most reliable, domestic boilers on the market.
It can be stressful when your boiler plays up or a fault causes your boiler to stop working. We have created this handy guide for Worcester Bosch Boiler error codes, which will help you identify and maybe resolve some of the problems in your old boiler.
Your boiler will flash with a warning triangle and a static fault code. Pressing the reset button on your boiler will clear this fault.
Your boiler will stop working and will not show any code on display. Press the return/spanner button and you will be able to find an error code. The error code will clear automatically when the fault clears e.g. the boiler is waiting for an action such as cooling of an area and error will be resolved once this is done.
This is an alpha numeric code that will indicate the fault group.
This is a three-digit number. It is not displayed but can be accessed from the info menu by pressing spanner/return button.
This is displayed with the letter H followed by a number. This boiler error is not a fault itself but advises that the boiler need some attention. This fault will not stop your boiler for operating.
Boiler locking fault code
9A Boiler has been fitted with incorrect heat control module (HTM).
9U Code plug is faulty or not connected.
B7 Control board need replacement.
C6 System is running too slow or too fast.
D1 sensor could be disconnected, wet or damaged. Boiler will block for 300 seconds.
D1 Boiler is overheating.
E2 The flow sensor is disconnected or damaged.
E5 Primary flow sensor has overhead.
E9 The main heat exchanger has overheated as the main temperature is 150 degrees.
E9 Flue gas thermostat has overheated.
E9 Failure after ignition attempts. Boiler will wait for 30 seconds before making another attempt.
EA Failure after ignition attempts. Boiler will wait for 30 seconds before making another attempt.
EA A blocked sump or strong wind in the flue.
EA Gas valve coil has been disconnected.
EA Flame has not extinguished within first 4 seconds.
EA Pump is not detecting water. Check pressure gauge and re pressurize to 1 bar.
Worcester Bosch Blocking error codes
A1 Little or no water in system. Check pressure gauge and re pressurize to 1 bar.
C1 Faulty fan, Fan is not working.
EA No flame is detected, boiler will block during 4 attempts before going to locking fault.
EF Boiler is operating at minimum burner load and there is higher flow temperature of 18 degrees.
260 Disconnected sensors or no water content. Check pressure gauge and re pressurize to 1 bar.
No Code Air lock.
To detect wocester boiler problems you can use our guide, however if you still have boiler problems, then you should call a gas safe engineer to diagnose the exact cause.