Worcester Bosch Fault Code EA

This page contains the information required to help repair and diagnose the fault codes being shown on the boiler display. The following table will take you through the fault finding sequence for rectifying a Worcester Bosch boiler with this fault code

EA and RESET button and fault indicator LED are flashing. During operation: flame not detected.

StepCheck Action
1Is a burner flame visible? yes: go to step 5
no: go to step 2
2Is the gas cock turned on? yes: go to step 3
no: ▶  Open the gas valve.
▶  Press the reset button for 3 seconds and release it. After releasing the appliance re-starts.
EA? go to step 3
3Is there air in the supply pipe? yes: ▶  Vent supply pipe.
▶  Press the reset button for 3 seconds and release it. After releasing the appliance re-starts. EA? go to step 4
no: go to step 4
4Natural gas models : measure gas supply at gas valve. Is the pressure OK according to technical data? yes: ▶  Is correct code plug fitted? If not, fit correct code plug (see Appendix).
▶  Press the reset button for 3 seconds and release it. After releasing the appliance re-starts.
EA? go to step 5
no: ▶  Check working pressure at appliance to eliminate pipe work problems.
▶  Check pressure at the building supply pressure regulator, inform gas company if outside correct range.
▶  Press the reset button for 3 seconds and release it. After releasing the appliance re-starts.
EA? go to step 5
LPG models:
is the flow rate of the gas supply to the appliance correct?
yes: go to step 5
no: ▶  Is there enough gas in the supply cylinder?
▶  Is there air in the supply pipe?
▶  Is the supply pressure OK? (if supply pressure outside correct range, inform gas supplier)
▶  Press the reset button for 3 seconds and release it. After releasing the appliance re-starts.
EA? go to step 5
5▶  Switch OFF the appliance.
▶  Disconnect the boiler power connection.
Is the earth connection correct?
yes: ▶  Reconnect the appliance power connection.
▶  Switch ON the appliance.
EA? go to step 6
no: ▶  Correct the electrical connection.
▶  Reconnect the appliance power connection.
▶  Switch ON the appliance.
▶  Press the reset button for 3 seconds and release it. After releasing the appliance re-starts.
EA? go to step 6
6Is the condensate trap blocked? yes: ▶  Clean out condensation trap discharge pipe.
▶  Press the reset button for 3 seconds and release it. After releasing the appliance re-starts.
EA? go to step 7
no: go to step 7
7Is diaphragm in air/gas manifold fitted correctly (see installation instructions)?
▶  Open air/gas manifold.
▶  Check diaphragm for correct orientation, soiling and splitting. Is diaphragm OK?
yes: ▶ Close air/gas manifold (see installation instructions).
go to step 8
no: ▶  Insert diaphragm in the fan intake tube as per installation instructions so that the flaps open upwards.
▶  Close air/gas manifold (see installation instructions).
EA? go to step 8
8Check the gas valve.
▶  Switch OFF the appliance.
▶  Un-plug the connectors from the gas valve.
▶  Measure the gas valve coils I and II electrical resistance.
coil I : R = 170  40  ? coil II : R = 400  50  ?
▶  Remove gas valve and check inlet filter for blockage.
yes: ▶  Reconnect the connectors.
▶  Switch ON the appliance.
▶  Press the reset button for 3 seconds and release it. After releasing the appliance re-starts. EA? go to step 9
no: ▶  Turn off gas valve.
▶  Disconnect the boiler power connection.
▶  Change the gas valve.
▶  Open the gas valve.
▶  Reconnect the connectors.
▶  Reconnect the appliance power connection.
▶  Switch ON the appliance.
▶  Check appliance for leaks.
▶  Press the reset button for 3 seconds and release it. After releasing the appliance re-starts.
EA? go to step 9
9Problem with flue?
▶  Check CO 2 level in combustion air in the flue
(with outer casing fitted).
Is the CO 2 level above 0.2%?
▶  Perform a fan pressure test
(as described in the installation manual).
▶  Open up heat exchanger - is it dirty?
yes: ▶ Check flue installation for agreement with the instruction manual.
Then:
▶ Press the reset button for 3 seconds and release it. After releasing the appliance re-starts.
EA? go to step 10
no: go to step 10
10Is flue gas CO 2 level incorrect? yes: ▶  Adjust to correct level.
▶  Press the reset button for 3 seconds and release it. After releasing the appliance re-starts.
EA? go to step 11
no: go to step 11
11▶  Select in the second service level the service function 8.F
(Permanent ignition).
▶  Select the value 1 and store.
Check the permanent ignition at the electrodes (without gas). Is it OK?
yes: ▶  Select the value 0 and store.
▶  Exit the service function.
go to step 12
no: ▶  Select the value 0 and store.
▶  Exit the service function.
go to step 15
12Ignition cable connected to ignition electrodes? yes: go to step 13
no: ▶  Reconnect lead.
▶  Press the reset button for 3 seconds and release it. After releasing the appliance re-starts.
EA? go to 13
13Ignition cable connector engaged in control panel? yes: go to step 14
no: ▶  Switch OFF the appliance.
▶  Engage ignition cable connector in control panel.
▶  Switch ON the appliance.
▶  Press the reset button for 3 seconds and release it. After releasing the appliance re-starts.
EA? go to step 14
14Is the ignition cable damaged? yes: ▶  Switch OFF the appliance.
▶  Change the ignition cable.
▶  Switch ON the appliance.
▶  Press the reset button for 3 seconds and release it. After releasing the appliance re-starts.
EA? go to step 15
no: go to step 15
15Electrode assembly defective?
▶  Switch OFF the appliance.
▶  Remove electrode assembly.
Electrode assembly burnt out or cracked?
yes: ▶  Replace electrode assembly.
▶  Switch ON the appliance.
▶  Press the reset button for 3 seconds and release it. After releasing the appliance re-starts.
EA? go to step 16
no: ▶  Refit electrode assembly.
▶  Switch ON the appliance.
▶  Press the reset button for 3 seconds and release it. After releasing the appliance re-starts.
EA? go to step 16
16▶  Switch OFF the appliance.
▶  Disconnect the boiler power connection.
▶  Check if the 20-pin connector lead assembly is damaged.
▶  Change the connector lead assembly.
▶  Reconnect the appliance power connection.
▶  Switch ON the appliance.
▶  Press the reset button for 3 seconds and release it. After releasing the appliance re-starts.
EA? go to step 17
17The PCB is damaged. ▶  Make a note of the altered service settings.
▶  Switch OFF the appliance.
▶  Disconnect the boiler power connection.
▶  Change PCB control board.
▶  Reconnect the appliance power connection.
▶  Switch ON the appliance.
▶  Restore service settings previously noted down.

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