Kegged my Lager centre of valve bubbling.

Hi all I purchased a keg to put my homebrew lager into, it has been in the keg now for 2 weeks and I know that is a short time but the brew is flat. Moved the keg from the garage as this summer has been cold and put inside the house. The centre valve of the the keg where you would add Co2 is bubbling, the instructions mention that there is a safety valve if the pressure gets dangerous, but surely if the beer is flat then there is not sufficient pressure yet. What I would like to know is, is it normal for air to be escaping from the valve...
Mark

No, air should not be escaping. I would get some Keg Lube and put it on the seals. That should fix it right up.

Thanks for your help. will I need to add more sugar or just top up with Co2?