Has anyone had this fault in VCDS before? Car heaters work fine however I do slowly lose coolant has to be topped up every 3/4 weeks could this be why? 

Looks like a spurious code to me. No N279 in the circuits of a 2007 BLT engined Fabia.

In fact, I don't think any mk1 Fabia has such a blocking valve.

 

So I'll go with no, that's not why you're losing coolant.  

I hate to rain on your parade but a laptop will not tell you where you have a coolant leak, however the chances are it's the radiator bottom left corner which corrodes and eventually pinholes, that or headlift.

I doubt it’s headlift as one of the first mods I did was pd150 headbolts and it loses the same amount of coolant no matter how I drive it, I have noticed a wet patch in the bottom corner but not inspected properly, was hoping it wasn’t the radiator but if this code isn’t common and doesn’t mean anything then it probably will be the radiator, I’ll have to inspect further, thanks guys 

Have a good look at the thermoswitch too, a few inches above bottom hose connection. They like to leak too, but can be fixed by just tightening a little.

Will do mate thank you