Thanks I have looked at the engineers manual from the Ravenheat site which is not much cop and has no mention of red flashing lights unless there is a better one somewhere.
If my Boilers stat on the CH is turned upto full the after a wgile the boiler shuts off and the red light starts to flash and also does this with the hotwater. Also the downstair Rads will not get hot unless i turn them off upstairs even after bleeding them all.
If I turn the stat down it...