Conventional Fridge Fridge-Freezer not getting Cold
If you have a fridge or fridge freezer and the fridge is not getting cold it will be one of the following problems:
1, The fridge thermostat is faulty and not cutting in at the required temperature. Fridge stats are not easy to test, so the best way is to bypass the stat to see if the compressor starts. To bypass the stat first unplug the appliance and remove the stat housing from inside the fridge compartment, once you have removed the housing you will see the stat inside. Some stats have 2 terminals some have 3, whatever yours has you will need to connect the compressor wire ( Black) to the live wire (Red or White). When you have bypassed the stat plug the appliance back in and switch on, if the fridge starts up and runs ok you will need to purchase a new stat.
Types of thermostats:
There are various types of stats fitted to fridges and fridge freezers, the most common being the VT9 (pictured below) this stat will replace most larder fridge stats and most conventional fridge freezer stats. If your fridge has an ice box inside then you will need a VC1 type stat which has different temperature ratings. If you have an older Zanussi or Electrolux fridge freezer with one compressor and the stat is in the fridge then you will need a Reverse Action stat, as these type of appliances have a solenoid valve fitted into the pipework near the compressor and the stat operates the solenoid.
If you are replacing your old stat with a VT9 and your old stat only has 2 terminals then connect the new VT9 using the terminals marked 4 and 6 only. When fitting any new thermostat take great care not to kink the capilary tube as doing this will render it useless.
2, If you have tried bypassing the stat, and the compressor did not start then you have probably got a faulty compressor. To test for this is quite simple just listen carefully to your fridge and if the compressor is at fault you will hear a faint hum followed by a click, you will need to be patient as once it has clicked it could be 10 mins before you will hear the hum again. The reason you hear a hum is because the compressor is jammed and the hum is the motor trying to turn, the click that follows is the thermal overload tripping. If you have these symptoms it will not be worth repairing due to parts and labour costs.
3, If your fridge has lots of snowy ice on the backplate this is a sign that either the door is not shutting properly and letting in warm air thus creating snow, or it could be that you have lost some gas from the system and the compressor is working over time trying to get the temperature down. BE ADVISED it is rarely worth getting your system regased unless a leak can be located, as the gas will only leak out again and you will have the same problem in 1 or 2 months.
Frostfree fridge not cold
If you have a frostfree fridge freezer and the freezer is ok but the fridge is warm then your appliance is not self defrosting correctly, and if you could see inside the back wall it would be full of ice, this ice is blocking the airflow to the fridge compartment and therefore your fridge is warm. A quick fix for this problem is to completely defrost the appliance to do this you will need to move your frozens to another freezer then switch off your frostfree at the plug and leave off for 48 hours with the doors open and a large towel in the freezer to catch the water. After 48 hours plug it back in and let it run for 4 hours and you should find it will be working fine again, but you may find you will have to do this procedure every 6 months or so.