the fridge is freezing up when the control knob is at lowest setting, ice is forming in a slab on the back panel inside the back of the fridge. It has a printed circuit board at the top and I cannot work out how the thermostat can be changed which is the probable cause of the problem unless you know otherwise. Will a simple re gass solve this problem or a new thermostat

FFF, November 2011

the ice build on the inside rear panel does indicate a problem with the heater circuit.if the f/freezer was opperating correctly the ice would be in a bead formation/frozen dots of ice covering the rear panel.at preset times the heater circuit cuts in,the compressor is disabled and the frozen beads of ice turn to water ,and then run down the rear panel,into the drainage channel ,through the bottom of the fridge via a pipe which connect to the evap tray ontop of the compressor.the water is then evaporated by the heat generated by the compressor.your heater circuit has failed ,hence the large build up of ice.you could try replacing the pcb/electronic T/stat.as this will also control the initiation of the heater circuit.I have had a look around various websites and have not been successful locating the pcb.I know two versions of the rd were manufactured,one for the uk market.now that your f/freezer has had a full 24 hour defrost I would refit old pcb and boot the f/freezer up.see how it goes.your f/freezer is quite a old model now .a repair to the heater/filter and regass in my opinion not worth it.also check the doorseal around the fridge door for condition,the seal should be sealed correctly all the way around and no splits,.check the door for total closure,any gaps splits food debris can impeed the door closure.that can cause the compressor to run and override the evap/timer/filter.same effect of leaving the door open all night.whatever you decide to do I wish you gud look.

mech monster, November 2011

Hi mech monster, thanks for all your help.. would you think it not cost effective to repair?

fff, November 2011

hi,your dial is the t/stat on that model .the over freezing is due to the heater,.as yours is a frost free version ,the temp dial can only control mid temp.the heater/filter is like a auto defrost and kicks in to prevent over freezing.the temp is preset and the heating circuit takes over to prevent over freezing .sometimes if the fan fails in the freezer the heater circuit is not engaged and over freezing can happen .the heater timer on your model is part of the system and is controlled and regulated by the compressor.you will need a engineer to replace the heater filter and regassing.I have the wiring diagram and the system operates differently to most uk versions. on most uk brands the heater circuit is activated by a heater timer usually found on the left hand side of the compressor .,yours is incorporated into the system and will need to be removed and a new one plumbed in by a engineer.this is something you cannot do yourself.hope you can understand that ,and I know you are thinking its a stat problem ,and you want to know where the stat is ,but yours doesn't have one its controlled by the pcb.

mech monster, November 2011

thanks mech monster.. but I have the printed circuit board apart with the control knob on it, but I thought it would be the thermostat within the fridge causing the problem, so how does the control knob sense the temperature? many thanks

fff, November 2011

the controll nob is the thermostat.regassing is not necessary as yours is freezing and you are just not able to controll it.if it was not freezing and the compressor was running constantly then that would be a sign of no gas due to a leak.

mech monster, November 2011