Problem with cannon chichester model no:10578G?

I have a cannon chichester cooker model no:10578G

When the bottom oven is on for a few hours for example when cooking a roast dinner I get a small puddle of water on the floor which seems to be caused by condensation, also get the water in the bottom of the oven at the front by the door.
Food always takes longer to cook than advised, have checked flow of gas & this is very variable, I can physically see the difference between gas mark 1 and 9.

I have taken the door seal off & cleaned but this has made no difference.

Any help or advise would be greatly appreciated