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Replacing a Double Door Refrigerator Thermostat
Replacing a refrigerator thermostat is fairly easy and almost everyone can do it themselves, there is just a couple of point you need to do the job yourself.
New thermostat
The refrigerator normally has three electrical parts inside the cabin.
1. Thermostat housing – containing the thermostat, lamp switch and lamp.
2. The light on the side of the cabin
3. Heater element, fitted at the back of the condenser(ice plate) gets tuned on when you open the door of the refrigerator
· Some units also have a ventilation fan inside the cabin.
The thermostat is actually a switch that switches the fridge compressor (black dome at the back of refrigerator) on and off
Something that is very important to remember is that the thermostat is not like a water tape that if you increase the Number on the thermostat you increase the refrigerant(gas) flow, not true – when that thermostat gets turned up it increase the TIME the compressor must run before it switches of again.
There for if there is a shortage of gas in the refrigerator it will not reach the temperature for the thermostat to switch off
General double door thermostat switch off at -8 degrees and on again at +6 degrees
Signs of refrigerant shortage
· Ice starts building up inside the fridge (on the evaporator plate)
· Ice blobs are formed in the corner of the evaporator plate
· veggies and milk starts to freeze inside the fridge
· Freezer cabin are working (freezing) fine but in the fridge compartment not.
· the food starts to smell
Inside the fridge cabin
There is normally 4 wires coming out of the side of the cabinet into the fridge cabin
1. Brown or red – live – Connecting to 6 (middle terminal) on thermostat. Most cases there is another wire that runs to your lamp switch and to the heater element at the back of the evaporator plate.
2. Black wire – live feed back to compressor – Connecting to no 4 on the thermostat
3. Blue wire – Negative – goes to other lamp terminal and heater element.
4. Green/yellow – earth – connects to the side of thermostat.
· White wire (sometimes different colors) – live feed to heater element – connect to no 3 on thermostat.
Wires at the back of thermostat housing
The only tricky part is not to bend the new thermostat capillary tub or let it get a kink in it because that will result the new unit not working.
Tips:
I normally disconnect the heater element wires completely from the thermostat because this unit also ages and in most cases it will start to develop problems soon after replacing the new thermostat ( but I will tell more in another post).
If the thermostat setting is correct (normally around 5 or the middle of the dial) there is no need a heater element in your fridge. The heater element is a costly item to replace and it is not necessary in most parts of the world especially in our country
When fitting, the new thermostat probe (front piece of tube) should touch the evaporator plate. Normally in the middle of the plate there are two plastic screws (that is where the probe is housed). Loosen them slightly and slide the old probe out and the new in. Loosen the two bottom screw on the side of the plate just to get your finger in behind the evaporator plate. Try to minimize the plate movement because this unit is made out of aluminum and can develop a gas leak very easily (if handled to much)
I wish you all of the best in replacing your refrigerator thermostat and remember to unplug your unit completely from the wall socket or power supply before working on it.
Regards
Pine
