ummm I see your point here..I believe the F4 error is a problem with the condensate pipe.sometimes the pipe can become a little blocked with debris etc.or the pipe can freeze up.both problems can lead to the ignition/boiler not firing.iam not a heating engineer but I was curious as to the fault,so I searched many forums and they all said this was the problem,have a look in the users manual.
ozone, December 2011
