is thermostat working ?

[kev_7680]

I have a vendo-39 i picked up a few months ago.I changed the outer and inner gaskets and turned it on this week.It seems to be running constantly,I set it between 2 & 3 and the pop is cold but doesn't seem to cut out.I have been doing some reading that said my problem might be the cut in and cut out screws.I looked and don't see any screws.It has been on a week around 3-4 and when i look its running.If i turn it towards 2-1 it doesn't shut off until it hits off.What can i do?I have attached pic not sure if its original or has been replaced at somepoint.the drum is full and have a few back ups on bottom.how can you tell if its working corect?

[johnieG]

Looks like a modified vendo V63 T-stat mounted on the outer shell of the evaporator housing, I've never seen an original mounted like this, the sensing capillary tube should go up inside the evap' coils themselves inside a small tube.  the shell will never get cold enough to cycle the T-stat  (and therefore the compressor) off.

[kev_7680]

So i just have to unscrew it from the outside and run it on the inside?What do i use for a small tube on the inside?

[collecture]

Most all of the early model 39's I've seen were like this.
The top pic is of a machine I refurbished for a local charity organization a few years back - it cooled and cycled fine with the contact type t-stat.

[johnieG]

Thanks Collecture for the clarification, as I said, I've never personally worked on this type Thermostat mounting, & seeing the pic's of the other machines helps clear that up. 

Hmm, so if the pop's cold, but the machines not cycling off, and it's not so cold that it's freezing the bottles, then machine could be light on a charge (of freon) or sounds like it's time to replace it. (the thermostat)  so what's the actual measured temperature inside the machine?   A 2-3 setting on the T-stat is quite "warm" relatively speaking. So I'd expect it to cut-off quite soon in say the 38-40 degree range...

[kev_7680]

So the t-sat is set up right?On another thread i read where a guy unscrewed the temp wand and put it in a cup of ice and waited to see if it shut off to see if therm was working.It has been on all night and the t-sat is set On #2 and the inside temp is 7 degrees celsius(45degrees fahrenheit)when i opend it today the bottom fan was off but turned back on in about 10 sec with door open...should i try the ice suggestion or how else can i check to see if its working?I deffinatly dont want to fry the compressior...thanks kevin

[johnieG]

The cup of ice water test only works for T-stats that are "air temp" types that is to say they operate/sense the temperature of the cabinet directly in the free air (and aren't directly connected to any metal in the cabinet area.) they operate in the range of 32-45/F (typically, some models do vary  )

Yours however is a "contact" type it reads the temperature directly off of the evaporator housing (which is colder that the air temperature blowing through it) so it's typical cut-off range is going to be colder, approx. 26-28 degrees Fahrenheit, so as you can see a cup of ice water @ 33-34/F isn't going to do it.

I have used a cup of cracked-ice & salt to give a quick go/no-go test of contact type T-stats.  or a can of "freeze-spray" used to test electronic components, it may be bought at Radioshack, or you could use a can of "air-duster"   from an office supply store, just hold it upside down to get it to blow out cold liquid freon ( R134a) onto the sensing tip. this will tell you it's working, but it's not an accurate "range" test.

[globalcompressors]

use a thermometer... what is the temperature of the box?

if you are reaching 30 to 35 degree, break down and by
a $30 thermostat...problem solved!

[kev_7680]

So should i turn it up to #7 and see if it gets to 30 to 35 degree or just buy a new tsat?Also if i do need a new one should i unplug it untill i get a new one?I just re checked it and its been 2 hrs on #2 and the bottom fan is on but the temp inside stayed at 46f (7c).....does that mean it is working if it is maintanning same temp?Again thanks for all your help guys ....kevin

[globalcompressors]

it's working IF the unit is cycling on and off at 46 degrees.
sure, try a higher number, 5 or 6, and let it run. as long
as it continues to cycle...no problem.


if it's at 46 degrees and not cycling...there could be a compressor/freon
issue.