Well - I've identified the problem - it was the CH flow micro switch not actually making a contact when the pin came out.
The Ideal help desk gave the response as soon as I reported the diags. so I guess its a known problem. I simply adjusted the micro-switch wand to connect earlier. I would...
Hi, Im having problems with the above boiler which has worked continuously & smoothly since 2005.
Fault symptoms started with intermittent hot water going cold mid flow. Turning tap off and back on cured that.
Then after a couple of weeks, the heating stopped working mid operation as well...