Worcester Bosch Boiler Problems, Fault and Error Codes

If you have found this page then chances are you have an issue with your Worcester Bosch Boiler. It may have stopped working, or not be operating correctly and may be displaying a fault or error code. Whatever the problem you shouldn’t ever try to fix the boiler yourself, leave that to Gas Safe certified engineers like us to fix, repair or replace any gas appliance such as a boiler. However some issues can be disagnosed using the Worcester Bosch boiler fault or error codes, which helps us diagnose the problem quicker for you.

If your boiler or heating system develops a problem, your boiler may go into a safety lock-out mode and display a fault code, see below for further details. Once you have this code please call us and we can then arrange a visit.

Please do not use this information to repair the boiler yourself it is for information only. If you have an issue with your boiler or heating system then please call us to arrange a repair call out.

 


























Error
Types		 Fault
Display		 Repair
Required
Fault Error An alpha-numeric fault code will display indicating the fault group (see below) Do not investigate the issue further as it may be hazardous to do so. Call us to diagnose further.
Locking Error Flashing warning triangle and fault code.
A (static) cause code will also be displayed.
Diagnose fault from fault code (see below).
Once fixed press reset button on boiler.
Blocking Error The boiler will stop operating with no fault data showing on the boiler display panel. Access the ‘Info menu’ by pressing the spanner/return button to find the ’cause code’.
 In some cases a blocking error may change to a locking error after a defined time period. The condition clears automatically when the associated fault clears e.g. waiting for an area to cool the ‘Blocking error’ will clear.
Cause Error Display shows a three digit number.
Cause code is accessed in the info menu via the spanner/return button if the boiler is operating normally and during a Blocking Error. During a locking error the cause code flashes on the display.
Maintenance Code Shows with the letter H followed by a number. This is not a fault that stops the boiler from functioning but does require a boiler engineer to look at the boiler to prevent further problems. Some common H codes are listed below.

Click to Call a Worchester Bosch Boiler Engineer
on 07920 774 209

 
















































































































































































Fault
Code		 Cause
Code		 Fault
Description		 Possible
Cause		 Repair
Required
9A 362 Heat Control Module Incorrect Heat Control Module fitted. Repair or replace heat control module.
Please call us for a quote.Repair or replace heat control module.
Please call us for a quote.
9U 233 Heat Control Module Code plug problem, faulty or not connected. Code plug requires reseating or replacement.
Please call us for a quote.Code plug requires reseating or replacement.
Please call us for a quote.
B7 257 Internal error Control board fault. Replace control board.
Please call us for a quote.Replace control board.
Please call us for a quote.
C6 215 Fan problem Fan running too fast. Diagnose fan problem and fix or replace.
Please call us for a quote.Diagnose fan problem and fix or replace.
Please call us for a quote.
C6 216 Fan problem Fan running too slow. Diagnose fan problem and fix or replace.
Please call us for a quote.Diagnose fan problem and fix or replace.
Please call us for a quote.
C7 214 Fan problem Fan not running at all. Diagnose fan problem and fix or replace.
Please call us for a quote.Diagnose fan problem and fix or replace.
Please call us for a quote.
C7 217 No airflow detected during a defined period of time Fan not running or airflow blocked. Diagnose fan or blockage problem and fix or replace.
Please call us for a quote.Diagnose fan or blockage problem and fix or replace.
Please call us for a quote.
D1 240 Return sensor error Sensor wet or damaged – boiler will block for 300 seconds before this boiler error is shown. Issue requires investigation.
Please call us for a quote.Issue requires investigation.
Please call us for a quote.
D1 241 Return sensor error Retrun sensor disconnected or damaged – boiler will block for 300 seconds before this boiler error is shown. Issue requires investigation.
Please call us for a quote.Issue requires investigation.
Please call us for a quote.
D1 286 Return temperature too high Boiler overheated. Issue requires investigation.
Please call us for a quote.Issue requires investigation.
Please call us for a quote.
E2 222 Flow sensor short circuit Flow sensor shorted or damaged. Issue requires investigation.
Please call us for a quote.Issue requires investigation.
Please call us for a quote.
E2 223 Flow sensor open circuit Flow sensor disconnected or damaged. Issue requires investigation.
Please call us for a quote.Issue requires investigation.
Please call us for a quote.
E5 218 Flow temperature too high Primary flow sensor overheated. Issue requires investigation.
Please call us for a quote.Issue requires investigation.
Please call us for a quote.
E5 332 Primary flow sensor overheated Primary flow sensor has exceeded 110°C Issue requires investigation.
Please call us for a quote.Issue requires investigation.
Please call us for a quote.
E9 219 Safety sensor temperature too high Main heat exchanger overheated – max operating range is 105°C Issue requires investigation.
Please call us for a quote.Issue requires investigation.
Please call us for a quote.
E9 220 Safety sensor short circuit Main heat exchanger maximum temperature sensor has failed. Issue requires investigation.
Please call us for a quote.
E9 221 Safety sensor open circuit Main heat exchanger maximum temperature sensor has not been recognised. Issue requires investigation.
Please call us for a quote.
E9 224 Maximum temperature thermostat activated Flue gas thermostat overheated. Issue requires investigation.
Please call us for a quote.
EA 227 No flame detected after ignition Failure of four ignition attempts. The boiler waits 30 seconds before another four attempts are made. Do not interfere and allow the boiler to go through the process. If the boiler can’t establish a flame and is stuck in this cycle switch the boiler off and call an engineer. Please call us for a quote.
EA 229 Loss of flame signal during operation An established flame has been extinguished.
Some example causes of this:
Blocked sump/condensate trap.
A strong wind into the flue.		 Do not attempt to empty sump or condensate trap.
Please call us for a quote.
EA 234 Gas valve error Gas valve coil disconnected Issue requires investigation.
Please call us for a quote.
EA 261 Ignition timing error No flame established during initial 4 second ignition period. Issue requires investigation.
Please call us for a quote.
EA 338 Too many short burner starts without confirmation Pump is not detecting water – check pressure gauge and repressurise to 1 bar. If your boiler has lost water pressure then there may be an additional water supply problem.
Please call us for a quote.
H11
Hot water outlet sensor defect Sensor may be defetvice or system blockage or other system issue may cause this error. Hot water can still be drawn but with less control. Issue requires investigation.
Please call us for a quote.
H13
Maintenance interval expired The Service interval function has been set to a specific time for your boiler i.e. 1 to 72 months and that time has expired. Menu 2.5F allows this feature to be set (1 to 72), a 0 will disable this function.
 We do not advise you to ignore your boiler maintenance programme. It will extend the life of your boiler and heating system.
Please call us for a quote.

Click to Call a Worchester Bosch Boiler Engineer
on 07920 774 209

 


















































Fault
Code		 Cause
Code		 Fault
Description		 Possible
Cause		 Repair
Required
A1 281 Boiler water pump running in air or stuck. Low water in the system or system dry – check boiler pressure gauge and repressurise to 1 bar. If your boiler has lost water pressure then there may be an additional water supply problem.
Please call us for a quote.
C1 264 Airflow from fan stopped during boiler operation. Fan fault, or blockage. Diagnose fan problem and fix or replace.
Please call us for a quote.
EA 227 No ionisation detected after ignition No flame detected. The boiler will block during 4 attempts then fail over to a Locking fault. Diagnose problem and fix or replace. Components as required.
Please call us for a quote.
EF 349 Central heating, boil detect – Large delta T despite minimum burner Boiler is operating at minimum burner load with a greater than 18°C Flow & Return temperature difference. Diagnose problem and fix or replace. Components as required.
Please call us for a quote.
No code 212 Safety or flow temperature rises too fast Air lock or reduced water content – check pressure gauge and repressurise to 1 bar. Diagnose problem and fix or replace. Components as required.
Please call us for a quote.
No code 213 Temperature difference between supply and return exceeding limit Air lock or reduced water content – check pressure gauge and repressurise to 1 bar. Diagnose problem and fix or replace. Components as required.
Please call us for a quote.
No code 260 No temperature rise after burner starts Sensor disconnected or no water content – check pressure gauge and repressurise to 1 bar Diagnose problem and fix or replace. Components as required.
Please call us for a quote.

Click to Call a Worchester Bosch Boiler Engineer
on 07920 774 209

 

Ark Heating Solutions covers are accredited Worcester Bosch installation experts and trusted boiler, heating and plumbing experts. With over 15 years expertise servicing Bordon, Whitehill, Farnham, Aldershot, Camberley and the surrounding area. If your Worcester Bosch boiler requires replacement, repair or diagnosis then please call us.