worcester greenstar r30 he fault code ae

[greengas]

hi , i have a bit of a problem , i attended a boiler breakdown today on a worcester greenstar r30 he , fault code ea , which indicates flame detection error ,now i checked continuity across the probe to harness , no resistance , checked flue gases ,ok ,air intake,ok , gas inlet pressure ok ,condence ok ,this would indicate to me pcb,changed ,still the same i even changed the probe block still the same ,can anyone help cheers

 

[Jamespl]

EA can be caused by a number of things. Check the flame sence electrode and make sure it's ok, condensate pipe could be frozen or blocked. Also there is what's called a bearing plate by the fan and they can stick. Remove the fan and feel up the pipe on the heatcell. If its intermittent it could also be a gas valve. While your at it chech the fan de-pressure remove the white nipple off the black plastic under the fan and put your manometer tube on it. It will give you a minus reading. Check the instructions as to what it should be, if it's under the heatcell may been cleaning.