Fridge is a Kelvinator impression series c500dr, serial number 75143256; when the fridge is on its defrost cycle the water does not dissappear so as to evaporate through the rear of the fridge, it runs down the interior face of the unit and fills the bottom tray until overflow occurs is there a blockage?

peter, January 2013

The drain from inside comes out at the rear just above the compressor where the water is caught to be evaporated by the heat from the compressor.
I just get a little piece of hose and put over it (make a good seal) and blow up it back into the fridge, will clear it better than trying to poke it clear.
Then wipe up any spill over in the fridge.

Fridgy, August 2014

Yes there is a blockage - I can see it from here.

Food debris has got into the drain hole - get something flexible and poke it clear.

Give the whole fridge a good spring-clean - I did mine two weeks ago and felt much better for having done it.

Good luck...

Peccavi, January 2013