proline slim larder fridge from comet - dont know model ?

Limited to slim fridges due to kitchen spaces - usually mean cheaper brands only available .Had for 3 yrs aporox and always quite full of food! Water ,not ice , been collecting at the lower ' channel' at back of fridge - needs mopping out each day so doesn't leak out of fridge .Will I need to replace the fridge as i suspect ??? The setting is on 4 half - which is recommended . Hope you can help , thanks