Snack Man 2000 Posted August 9, 2017 Share Posted August 9, 2017 I have an older 721 that began freezing some drinks in the center a year ago. George at tech support had me adjust the chute and raise the temp. That solved the issue until now. Now there's lots of ice on the right side of the evaporator coils. Only on the tubes on yhe right, not the front. Raised the temp to max, and it was good for a few weeks. It's back again. George said to replace the refrigeration deck. Is he correct, or is the temp sensor bad? Link to comment Share on other sites More sharing options...
AngryChris Posted August 9, 2017 Share Posted August 9, 2017 Sounds correct. Those are usually completely different problems, and you need to put the thermostat back to where it was. Turning it up won't ever solve anything but it could cause the soda to freeze when you change the deck. Link to comment Share on other sites More sharing options...
Snack Man 2000 Posted August 9, 2017 Author Share Posted August 9, 2017 By turning the temp up, I mean to the hottest setting which is 4 bars on this 721. Link to comment Share on other sites More sharing options...
AngryChris Posted August 9, 2017 Share Posted August 9, 2017 I have never adjusted a vendo 721,but I'm making a point that adjusting the thermostat won't resolve anything. The thermostat basically controls the temperature, so if the machine isn't cooling properly and the thermostat is good, then the problem is with the deck. Changing the thermostat temperature doesn't change how the system works, it just sets a temperature. So if one setting is approximately 36 degrees, turning it down might ask the deck to go lower such as 30 degrees. It may seem like a fix but it's not. If the deck has a problem, you are potentially making it worse. I ONLY change thermostat settings when diagnosing a machine, replacing a thermostat, or adjusting a temp sensor setting when necessary. Link to comment Share on other sites More sharing options...
Snack Man 2000 Posted August 9, 2017 Author Share Posted August 9, 2017 George at Vendo suggested changing the setting to high. I believe it did buy me a year or so before having to repairing the deck. I repair them myself, so I'll change it out for one that I refurbished. Link to comment Share on other sites More sharing options...
AngryChris Posted August 9, 2017 Share Posted August 9, 2017 I don't do my own refrigeration work, but if you do your own, I would assume that you would know what's wrong with it. Link to comment Share on other sites More sharing options...
AngryChris Posted August 9, 2017 Share Posted August 9, 2017 And I'm 100% sure that changing the thermostat did not buy you time. If it's a slow leak, then you just had that much time. Link to comment Share on other sites More sharing options...
Snack Man 2000 Posted August 9, 2017 Author Share Posted August 9, 2017 The machine was freezing up a over a year ago when I first turned up the settings. It didn't freez again until now. The refrigeration deck really isn't that hard to work on. Link to comment Share on other sites More sharing options...
AngryChris Posted August 9, 2017 Share Posted August 9, 2017 Freezing soda and a freezing evaporator are two different things, so when you say you turned it up when it froze, it's very confusing. Freezing cans is caused by either a setting that's too cold or a bad thermostat /temp sensor that's letting the compressor run too long. the solution is either to replace the faulty thermostat/temp sensor if it's bad. A thermostat that's good but set too cold is user error. It won't get that way on its own. Ice on the evaporator as you describe is usually an indicator that the deck is low on refrigerant, but not an indicator of how low or how bad the leak is. It could stay like that for a year and still cool. The catch is that if the ice gets big enough and touches the thermostat line, it will create a false reading telling your thermostat that it's ice-cold in the cabinet. That causes your compressor to turn off, inadvertently making the cabinet warmer because its not running as long as it should. Of course, Turning the thermostat to a temperature colder than the ice will temporarily mask the problem but now you're making the compressor work harder to keep the machine colder AND with insufficient refrigerant. So, by turning it up, you haven't bought time, you've just put a greater burden on the compressor. If anything, it seems like you'll kill it faster by doing it that way. The simple fix is to pull the deck out, get the leak repaired, recharge it, and put it back in the machine. Turning the thermostat up is the equivalent of driving faster to get to a gas station because you don't want to run out of gas. In reality, you're going to run out faster at a higher speed. Link to comment Share on other sites More sharing options...
AZVendor Posted August 9, 2017 Share Posted August 9, 2017 Don't replace the cooling deck - George isn't very in tune with real life fixes for this - but have a certified refrigeration tech come out to recharge it. Link to comment Share on other sites More sharing options...
Snack Man 2000 Posted August 9, 2017 Author Share Posted August 9, 2017 I hired a certified commercial refrigeration guy to repair a Dixie Narco deck that was just out of warranty. He claimed he found a leak, and put a vacuum on it for only a couple of minutes. Then he charged it and charged me $179. 2 weeks later it was out of refrigefant again. He refused to stand behind his work. So then I had to buy a nee deck for $500. I will be putting stop leak and charging my own units from now on. Link to comment Share on other sites More sharing options...
AZVendor Posted August 9, 2017 Share Posted August 9, 2017 DO NOT put stop leak into refrigeration systems unless you want to replace them on a regular basis. That will contaminate the system and cost you not only a compressor but the evaporator, condenser and all the freon lines. You need to find a different refrigeration tech who knows how not to rip people off. If he had evacuated the system due to a found leak that he repaired then he should have verified it could hold a deep vacuum for at least 2 hours before recharging it. The fact that he won't stand behind his work on a sound unit like yours (assuming there weren't any obvious issues with the quality of your unit) then you know to never use him again and you should probably dissuade anyone else from using him. It sounds to me like you didn't know all the ins and outs of this kind of repair and he took advantage of that. The first thing I do for anyone wiith low freon is tap the system, put my low side hose on and recharge the system to the required low side pressure. I watch the gauge to see if there are any signs of bad valves and I also know when it should have received enough freon to be charged so that if it still shows low pressure then I know the valves are bad in the compressor. This is with the caveat that this might not be a long term fix. If the freon leaks down in less than 6 months then it's a large enough leak to be found with a sniffer. The longer you go past the 6 month point the smaller the leak is and the harder it is to find. The tiny ones often can't be sniffed out so UV dye must be injected into the system before it's recharged again. Once it again runs low on gas you should be able to find the leak with a black light at that point. In these cases there is no warranty for slow leaks because you never know what kind of leak you have to begin with. There is always a tendency for gas to slowly escape from sealed systems depending on the quality of the brazing and the copper lines. Link to comment Share on other sites More sharing options...
CajunCandy Posted August 9, 2017 Share Posted August 9, 2017 No stop leaks in decks! Link to comment Share on other sites More sharing options...
Snack Man 2000 Posted August 9, 2017 Author Share Posted August 9, 2017 I have seen quite a few that have been running for years with stop leak. Link to comment Share on other sites More sharing options...
AZVendor Posted August 9, 2017 Share Posted August 9, 2017 How do you know? Are you a service man or is someone just labeling them that way without you knowing? I can tell you that even if one runs with stop leak, when it does eventually stop running it will be junk and not repairable. It sounds like you have a local scammer who is trying to create future work for himself. We have one of those here who regularly overcharges units he repairs and uses Hotshot instead of real freon or an accepted hybrid gas in the hopes that he gets a future service call from it. I have had to remove gas from many of his units to get them to run properly at the correct pressures. Just because someone does a repair incorrectly over and over doesn't make it a proper repair. Don't be fooled by that. Link to comment Share on other sites More sharing options...
Snack Man 2000 Posted August 10, 2017 Author Share Posted August 10, 2017 I have one that I did over a year ago. Here is a repair company that does it. Link to comment Share on other sites More sharing options...
Snack Man 2000 Posted August 10, 2017 Author Share Posted August 10, 2017 Even the commercial refrigeration guy I hired said it's hard to fix tiny leaks, but mine was obviously not since it lasted 2 weeks. Link to comment Share on other sites More sharing options...
Snack Man 2000 Posted August 10, 2017 Author Share Posted August 10, 2017 I also did a 14 year old Trane heat pump that a company said needed to be replaced. It's still running 4 years later. NuCalgon is awesome. Link to comment Share on other sites More sharing options...
AngryChris Posted August 10, 2017 Share Posted August 10, 2017 This reminds me of people who say they can save money on taxes by not reporting income from vending machines. Link to comment Share on other sites More sharing options...
Mehehe Posted August 10, 2017 Share Posted August 10, 2017 Always considered any of that leak stop/tire slime/etc. the same... great if your about to sell whatever your using it on... make it someone else's problem. Link to comment Share on other sites More sharing options...
Snack Man 2000 Posted August 10, 2017 Author Share Posted August 10, 2017 Well it saved me over $9000 and the hassle of having my heat pump replaced. Most refrigeration companies will put the stuff in if you request it. Our local Trane dealer keeps NuCalgon in stock. Link to comment Share on other sites More sharing options...
Mehehe Posted August 10, 2017 Share Posted August 10, 2017 Sweet, well good luck on the Vendo Deck. Link to comment Share on other sites More sharing options...
AngryChris Posted August 10, 2017 Share Posted August 10, 2017 Hey look... if it works and saves you money, that's fine, but unless you are certified in refrigeration, then you're not supposed to be legally allowed to work on that stuff as far as I know, but that's you're problem and not mine. And I'm not saying I haven't been guilty of doing things that I wasn't certified to do, but refrigeration is not that simple. Whatever works for you, that's great... I just know that a lot of people go through a fair amount of classes to get certified to work on refrigeration systems but here you are asking George what's wrong with your system. It seems as though you don't fully understand a refrigeration system. Again, if it works for you, great, but it's not something I would ever recommend anyone do on this forum. It's like using duct tape for a leaky water line. It might work for now, but it's not the proper method and it's bad advice in a general sense. Link to comment Share on other sites More sharing options...
Snack Man 2000 Posted August 10, 2017 Author Share Posted August 10, 2017 The reason for my post is because I haven't seen ice on one side of the coils that has lasted this long. Normally the unit will stop cooling shortly after. I figured someone here has ran into this befor and had some advice. As far as certification, I will be getting certified this winter. I have repaired many decks on my own, but plan on doing it as a business service. Link to comment Share on other sites More sharing options...
AZVendor Posted August 10, 2017 Share Posted August 10, 2017 Ice on the cap tube side of the evaporator will often be there until it's recharged or it ices over. You haven't seen many low freon conditions if you simply think that some frost immediately leads to the end of cooling. It's not typically the case. You just aren't ready to be a refrigeration tech yet. Schooling or not you should not be servicing other people's units if you haven't yet seen typical scenarios. Otherwise you'll be learning on your customer's dime. Link to comment Share on other sites More sharing options...
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