OK, picked up a Vendo 81D, not cooling properly.

[Bruce]

I recently picked up a 81D, it had been restored about 5 years ago. It had been idle for a little over a year, reportedly working when last used.

Previous owner contacted the company that refurbed it, and spoke with a tech there, a faulty thermostat was suspected, as AFAIK, that may be correct.

They tried to do some long distance troubleshooting, adjusting the cut out and cut in, but no success.

Now that the unit is in my possession, I let it sit roughly 48 hours because of the transporting it by laying it down factor, and I just started in on working on figuring this out.

I set the cut in to midrange, actually a little past that on the warm side, and set the cut out to the coldest it would go. I wanted it to try to get as cold as it could. (I figured if it started to chill, as it approached 34 or there abouts, I would back the cut out to that area before it crossed over into freezing.)

No luck, still not cooling. I have no idea if it is the thermostat, low coolant, or any other # of things. Hoping to get some insights on possibilities here.

Other info.

The fan is running.

The compressor seems to be as well, it vibrates, and after a bit of time, gets warm.

I touched a few areas in the upper cooling area, everything seemed to be room temperature.

I'll include a few pics, maybe your eyes will see something obvious I missed. There is some greening on the copper piping as you will see. Don't know if that is particularly problematic or not.
I'm an electrician by trade, is there any specs that would help me troubleshoot the thermostat, like disconnecting/isolating it and looking at the ohms readings as you go through the adjustments. I doubt it, but that is in my wheelhouse if I knew what the values were supposed to be.

Yes, it needs come cleaning, that's next.

Any help is appreciated.

[MoonDawg]

       The thermostat only comes into play after cooling has been achieved, first let's get it cold.
       The compressor getting warm, so it is working.
       The coils not getting cold on startup usually means low on freon.
       Since your compressor is not the original, copper lines recently had to be soldered to the evaporator.
       A pinhole in their solder job would slowly leak over time and the machine would keep running harder and harder each day, and the owner thought it was the T/S.
       It is very easy to remove the unit from the machine, then take it to a refrigeration shop and they will get you back up and running.

[Bruce]

The main reason I mentioned the T-stat and the cut out/in was I wanted all to know that I ensured that it wasn't in a position to have the cutout set where it would be doing its job and not letting it cool, like room temp. That is if the cutout even allowed a setting that high, which it probably won't.

Well that and because it was diagnosed by others as a possible cause.

I've heard that removing the cooling guts of the machine is pretty easy. It looks like the fan/compressor section is in the lower, the finned part (what is the proper name?) in the upper. Both will need to be removed, is it complicated in any way by a (I assume) hard line going from one to the other? Possibility of bending/kinking, right? Any tips?

Thank you

[Bruce]

    It is very easy to remove the unit from the machine, then take it to a refrigeration shop and they will get you back up and running.

I looked at it this morning after I got off work, (I work overnights) and I'm at a loss as to how removing the cooling system is easy. The top and bottom sections appear to be connected by Cooper lines, that have no disconnect. The top part doesn't appear to be hardware mounted, but rather it is bonded to the "case".

What am I missing/ not seeing or understanding?

[jholmgren]

I looked at it this morning after I got off work, (I work overnights) and I'm at a loss as to how removing the cooling system is easy. The top and bottom sections appear to be connected by Cooper lines, that have no disconnect. The top part doesn't appear to be hardware mounted, but rather it is bonded to the "case".

What am I missing/ not seeing or understanding?

I haven't done the cooling unit from an 81, but it is likely similar to my 44.  I have a guide here:
http://soda-machines.com/discussions/index.php/topic,20068.0.html

It comes out with both the upper and lower components still attached to each other - a home made stand is key to not kinking the lines.  Easy to knock together.

Jim

[BrianS]

There have been some discussions on this in the past.  Here is one with a few sample racks ranging from Grade A to Grade Just need to have an upper shelf to let the evap section sit on.

http://soda-machines.com/discussions/index.php/topic,11222.10.html

[Bruce]

I'm trying to do some smart troubleshooting before I commit to doing something as radical as pulling out the cooling deck. I'm thinking about trying to rule out the thermostat. What would happen if I eliminated the thermostat and just jumped the two wires together, just for a few minutes to see if it goes straight to cooling mode. My thinking being, if it does work then, that pretty much isolates the thermostat is probably the bad part. If it makes no difference, and the thermostat is possibly/probably okay and I should keep looking elsewhere.

Thoughts?

[MoonDawg]

      Yup! Tie those 2 wires together and let the machine run all night.

      If the compressor is working properly it will now never shut off............... but hey, that's another way to keep ice cream frozen! 

[Creighton]

Best to not and try to reinvent the wheel. Your machine though. Many answers and solutions can be found using the search tool. Not that difficult to master.
Creighton

[Bruce]

Best to not and try to reinvent the wheel. Your machine though.
Creighton

Obviously I don't want to do anything to damage the machine, I was just trying to be smart about getting it running.

Right now, there seems to be two main theories (could be more, haven't gone there yet) about what is going on with it.

One is pinhole leak, resulting in low freon. Or R-134 in this case, resulting in no cooling.

The other is a bad T-Stat, possibly stuck in cut-out mode or something like that, not allowing the unit to cool.

Using conventional thinking, I could order a T-Stat for $40 and shipping, and hope it fixes it, as I am sure it is non returnable. If it doesn't, out the $$ and still have my issue.

Or, I can pull the deck, (build the stand, etc) and take it to a pro for diagnosis and repair. If the system hasn't had/developed a leak, and it's the T-Stat, well, that was a lot of work and risk of further damage endured for nothing.

Slaving in a T-Stat seems to be the obvious first step, and after doing it it can quickly be called a good fix or ruled out. In my Air Force job we would do this all the time in troubleshooting. The cool part there was it was at no cost to us personally, and the supply system had no heartburn accepting back electrical parts in to the supply system. However, as a consumer, there is a monetary risk in this case.

The T-stat does something in the grand scheme of things, it either lets power go to some component under certain conditions, or takes power away. (If that's the case disconnecting it temporarily would serve the same purpose, to see the results)

I was simply trying to be smart, and see if I could quickly identify and confirm it as the culprit, or rule it out, that is all. I had no plans on letting the unit run for hours and hours, just long enough to see if it changed anything.

But before I acted, I wanted to float the idea around here to you folks who have much, much more experience on these units. I pictured possibly someone saying "yup, that's a real quick way to identify it if it is acting up", or even the flip side, "don't do that, and here is why...."

Bruce