Air Suspension died

[Glync]

Evening all
Coming back from Sheffield today I noticed the yellow/amber suspension light on (heart sinks)
The lift option is greyed out and the ride reverted to rock hard
I have checked the small fuse in the compartment by the passenger door, all ok. I then read all the threads I could find and set about looking for the fuse under the passenger side carpet! Thanks to Bex and her thread on a similar issue
Found it, tested it and it was dead, Result!

Managed to get one at Halfords (bought two in case 2.70 each)
Got home and just fitted it. All was ok tried the lift option and the car rose as normal and no lights. Took her for a brief ride out and within 100 yards of leaving home the light is back on again.
I haven't tried another fuse as I can't now be bothered tonight, already nursing a nice graze on my arm from fighting the carpet back into place

Anyone have any ideas what this might be, I have heard there is also a relay which plays up, could this be a cause of a blown fuse?
I can't hear any strange noises from the car and before the first time the light went out it was driving perfectly with no issues.

Any help or pointers very much appreciated as I really want to avoid the local Audi biys and their £100 plus VAT an hour
Cheers
Glyn