Was called to a 24i jnr. yesterday, showing a constant fast flash (4/sec). This occurs all the time even with no demand, (after reset obviously). The central heating still works ok but no hot water. Tested/replaced pcb, dhw sensor & flow turbine. I was led to believe that as soon as one of these boilers shows a fault the fan should run all the time that the fault is showing, this one does not. Ran all the checks with worcester tech. on the phone, no joy. Will try a new harness. Can anybody shed any light on what I have missed,please?
