whats a Freezer thermic signal switch?

[andyrattle]

Hello all sparkys.

My girlfriends freezer defrosted itself yesterday for no apparent reason.

I just took a look at the back and there is a little tiny box on a wire that looks like it should be attached to the radiator thingy, but was just hanging there. it clips nicely back on to the pipe but couldnt see exactly where it was.

Could this be the cause? There is a wiring diagram on the back that mentions thermic signal switch and im guessing this is what it is and the reason the freezer wouldnt freeze up?

Its a new world nw801fz built in freezer.

cheers

andy

 

[andyrattle]

Well that didnt work, unless ive clipped it to the wrong pipe? Hard to tell as no marks as to where it came from.

A laymans guess from me - if this is the thermal signaling switch and fell off would the freezer have burned its guts out trying to cool the freezer down as there was a constant signal its too hot?

 

[Evans Electric]

Have'nt a clue , Andy, is there not a Refridgeration Forum online ??

 

[RussellR]

It senses the temperature of the suction line to the coil and tells the compressor when to run, if it came undone you are right it would run the compressor too hard trying to reach temperature, but you would expect there to be a thermistor within the coil of the compressor to cut it out before it destroyed its self. Tha said sometimes domestic appliance don't have those levels of protection.

Put a meter across the power input of the compressor and see if the sensing circuit is calling for it to run, if it is chances are the compressor is u/s, however if it isn't then the sensing circuit is not working.

 

[andyrattle]

Thats useful thanks.

 

[andyrattle]

The compressor is hot so i assume its running? If it is its very quiet though, the fan is making more noise.

I havent put a meter across as im not sure which terminals are correct.

 

[RussellR]

Hi Andy

Do you have a circuit diagram for the fridge ? The compressor will get hot when running, however too hot can be bad also.

 

[andyrattle]

Thanks for input,

Theres a circuit diagram on a sticker on the back of the freezer. Left it on for couple hours, compressor was hot but didnt sound like it was running, and nothing got cold. Theres a fast freeze button (which bypasses the thermic switch i guess?) but pressing that doesnt make any difference.

 

[batty]

Sounds like you need a new one.

 

[RussellR]

SOunds like it might have lost it's gas charge. Unfortunately I think Batty's diagnoises may be correct ! They can be repaired, and recharged, but often when the circuit is open to atmosphere it does substaintual damage, and make them beyond economic repair. If it is a modern fridge the gases they use are flamable so repair needs to be done after the system is purged completely with Oxygen free Nitrogen. Unless it is a very expensive model I doubt repair would be economic.

 

[andyrattle]

Thanks all, given up and now looking for a new one.

Very useful forum - much better than an american one i tried!

Added to my fave links!

Hope you all have a good weekend

Guiness Drink