The fridge was working fine but it's been off for a few months and
then i transported it on its side (yes i know!) in a van where it was
left overnight.

Did you do the standard things to get it working again? You should stand
upright unplugged for 24 hours. Then you should run the compressor for only
about 30 seconds at a time, with 10 minute rests for a couple of hours. This
separates out the oil and the refridgerent.

Christian.