Chest freezer compressor always running

[peter p]

I have an old General Freezer (20 years old) that keeps running and never shuts off.
The freezer compartment freezes everything solid and my digital thermometer reads -24c.

I changed the thermostat but it does the same thing.

I have it on the lowest setting and if I turn the dial to off, wait a while then turn the dial the compressor turns on at about setting 5 with setting 7 being the highest.


Does anyone know why it keeps running?

[peter p]

Also,
the thermostat I used is a universal VF3 thermostat.

My capillary line on the old thermostat was about 24 inches long. On the replacement universal VF3 the capillary line is 72 inches long.

I stuck the 24 inches into the capillary tube and coiled the rest.

Can it be that the capillary line is too long and coiled?

[charlie patt]

most frost free freezers set to between minus 18 and minus 21 but because a chest freezer buids ice the internal temp runs between minus 25 to minus 30 so it aint getting cold enough his could be due to a fridge fault or at that age bad insulation on provision the capiliary is long enough always mark it before you pull it out my only concern a vf 3 is a twin compartment model in the uk but in canada i dont no can you advise

[chemi-cool]

Could your thermostat activate another component such as a relay which is faulty?
Is there any defrost timer that is stuck on cooling?

[mikeref]

The tube where the VF3 capillary fits into has detatched from evaporator therefore not sensing correct temperature.

[peter p]

My old thermostat had 3 terminals. One was for the freezer alarm light.
They discontinued that one (VS5) so they said I had to use the VF3 which had 2 terminals and no alarm indicator.

The thing is once I installed the thermostat and it ran for about 18 hours and the freezer shut off like normal.
After that it just keeps running.

I think it has something to do with the capillary tube.
I don't understand how it works but if you coil the excess and leave it in the compressor compartment how is the tube suppose to cool down and shut off the compressor with 100 degree compressor heat surrounding the capillary tube?

I'm going to try and leave the capillary tube coil on the outside of the compressor compartment away from the heat and see what happens.

[peter p]

The tube where the VF3 capillary fits into has detatched from evaporator therefore not sensing correct temperature.

Could be.
When I pulled the old one out it was covered in black.

[peter p]

I pulled out the cap tube and it was ice cold the whole 24 inches that was inserted.

I stuck 24 inches into the freezer and closed the lid.
The compressor cycled properly so the thermostat works.

I figure that the cap tube is too long and not cooling properly due to the length or its not cold enough in the wall of the freezer.

Still experimenting.

Feel free to give me your thoughts.

Thanks

[mikeref]

Thermostat tube length won't be a problem. The contact area on the insulation side of evaporator wall is the problem. 20yr old freezer, you could risk drilling a hole into freezer to rerun thermostat but if you drill into a pipe, it's all over red rover.