Avantco Refrigerator’s not cooling properly

[fixbear]

I forgot to ask the main question, is the condenser fans and compressor running?

[hailstone]

Yes both of fans are running. on both of the refer units.

On the large unit the condenser and evaporator fans are running.

I plugged the large commercial unit yesterday and the evaporator was icing up a bit on the edges on right hand side, I had the three fans down, after I reconnected the fans assembly it dispersed, the unit only cooled to 78 degrees. The compressor is hot, fan seems to be running as usual at the condenser and inside at the Evaporator.

Thank you Fixbear

[fixbear]

The compressor is hot, but is it running? Check the top tube on the condenser. It should be boiling hot. If the compressor is running and the top tube is not that hot, call a refrigeration tech. you probably developed a leak and is low on charge. But it still sounds like there is not enough air moving through the condenser and the compressor is tripping out on overload. Or it is not starting at all and tripping out.

[fixbear]

BTW, what make compressor is in it. Some of the Chinese machines us what used to be Danfoss SC’s They have a top compressor that is known to loose lubrication and have hard starts with age. I’m not a fan of that brand.

[hailstone]

wow I have been having nothing but trouble replying, the pop-up window just refuses to show up… and now here it is. I sent a ticket in.

Yes the condenser is very hot, the fan seems to be running good, Ill have to go check on the compressor brand.

I’m not so sure that the external fan was really doing much as it was a gradual increase in refusing to cool. I was leaning toward a sensor malfunction because it would run fine for a few days at first and a couple times after I had fiddled with it more it seemed to work. Just checking wire were tight. The big unit took months to finely not cool enough to use. The owner put the fan on it. Id shut it off, it seemed to be the same to me but i included it because she kept using it thinking it might be helping. the funny thing was she would put it on the left in front bottom in front of the louvers when the condenser is on the far right bottom and angled to the right some. this is a double door fridge so the external fan air wasn’t even close to the condenser.

The reason I don’t think its a leak, low on gas is because it would run fine for a time in between not running, same with the smaller unit. but then it would start getting warmer by the days then work, then not. until like yesterday only got down to around mid 70’s before I unplugged the unit. now it had been unplugged for about two months or so. So it was over winter that both units started their revolt… the big unit is in a hallway that in that time of year is fairly comfortable heat wise, this time of year it’s a little warm in the hallway.

looks by the context of your first post that you had maybe asked a question(s) prior to asking about the fans working? if so they did not show up.

the unit has not been moved or messed with except for me using an air compressor to clean the condenser’s and them placing the fan near it until I was checking wiring.

I was talking to a fella with limited experience yesterday, he was suggesting that the defrost maybe faulty, however you have to manually hit defrost on this unit. he thought that maybe it was stuck in defrost mode but again that doesn’t explain why it would function fine for a while. and the fact that it was cooling but climbing in temps by the days weeks. what I mean by that is it would work fine, cool to 34degrees but once opened a few times it would only go to say 40 degrees… then the next day cooled down to 34 until opened then to 46… and gradually increase in temps by the day until even overnight not getting down to 34degrees not even getting close. steadily increasing until it was in the 70s not hardly cooling at all. this didn’t matter with the external fan or not. and again this happened to both units except the smaller unit was way faster like a couple weeks where the larger took months. And at first over night it would cool down to 34 but after a few weeks even over night it still wouldn’t get down to 34. the wine/glass cooler is in a different room stays cooler, its in the main bar.

I remember the owner telling me that she had came in one morning and one of the door had been left open slightly. it seems that either this was the beginning or just coincidence of things to come, at any rate this seems to be around the time the big unit started acting up or shortly after.

The door seals are good no tears or folds, seals good. the double door is about 7 years old, bought new.

The smaller unit has been recharged a couple years ago.

One other thing I wanted to mention is you were helping me on the Fryer about a year ago Fixbear, that turned out to be the thermopile, I’ve gone through three now and another on order, doesn’t seem to matter what brand, the Robert Shaw went out the fastest. I’ve read others having the same problem on webrestraunt. I wonder why they are failing so fast and yet the other fryer is still working fine.

thank you again.

Ben

[fixbear]

It is of the utmost importance to follow my original troubleshooting post as it will tell us where to look.

As for Defrost, it is not used on coolers. It does nothing. The controller is built to work in both a freezer or cooler.

Now when it comes to the external fan, It has to move a lot of air thru the condenser. The lower tube on the condenser tells us if it is enough by the temperature. If you used air to clean the condenser, you have probably packed material into the center of the coil. We normally only use a brush sweeping down or a vacuum. Thats why I told you to check with a light if you can see through it in all areas.

Now when a door is left open, the humidity in the air forms ice and the cabinet will never cool till properly defrosted. The fastest way is to shut off the compressor and keep the evaporator fans running. But, I say BUT, if it iced up very badly, the ice places stress on the coils. I’ve seen cracks from that and leaks form. Unfortunately, that usually means a new evaporator as the cracks happen in a non-weldable area.

When a refrigeration device is built, it has a low side and a high side. During normal running the area from the compressor discharge to the metering device has to be rated for 450 psi. So, it is built heavier than the low side. The low side is only required to be 150 psi. So, some manufacturers save money by using lighter components. When the machine is running full time, the low side rarely sees more than 40 to 50 psi. However, when the machine is shut down, both high and low sides equalize at the vapor pressure of the particular refrigerant used. If the storage area is hot, pressures can exceed the 150 design pressure. This helps to make slow leaks that one never sees during normal operation. But also, one can find that dust and organic material in the condenser coil may develop a type of mold/fungus that will inhibit air flow. And can only be cleaned with a foaming cleaner. Light and temp of the tail coil.

As for destroying thermopiles on a fryer, usually the pilot is to high or the thermopile is mounted wrong and is in the burner flame. But more often it is a connection. They are not like a thermocouple. They have a very low failure rate. I’m 76 and I’ve only had to replace 2. A good DVOM is your best friend on this.

[hailstone]

Thank You Mr. fixbear, as mentioned your tutorial did not show up for the refer, in this thread, please scroll up its not posted. I’m not sure why. only the question you asked after that, that you forgot to mention in the tutorial did… I would so much appreciate if you could repost it, Please and Thank You!

I apologize for being a pain!

The compressor is made in Slovakia. I had made sure the fins were clear with a flashlight prior to original posting after I first cleaned it with the air it was only a little dusty being in the hallway, thinking it might be the issue. they are clean as a whistle inside guaranteed, can see right through. Thank you Ill make sure to only vacuum them in the future.

Thank you for the follow-up fryer info. as well. they had Campora propane tech working on the fryer before me, I asked Todd Campora tech and manager about the fryer and he stated I needed to replace the gas valve. When I asked why he stated they had replaced the thermopile twice prior so that makes 5 replacements now I think with a couple different brands. I don’t know how replacing the gas valve would help with the thermopile failures plus I think it was almost $300 to replace the gas valve. He did mention that they were having problems with the thermopiles and gave me a replacement for I think the second one I purchased from him that only lasted a month if memory serves. When I told him it was working with the new thermopile, he just said OK was all.

I double checked the flame and made sure its the same distance matching the other fryer yesterday, that I think has the original thermopile on it still. I did not replace the gas valve as the first replacement thermopile that I put on worked for a few months the second one not so long, third or fourth now I’m starting to lose count…will see.

sorry again for not posting timely I just could not get the reply tab to work again since you posted last. I’ve emailed and sent in a ticket. I’ve tried everything I could including using my phone instead of computer… the reply button doesn’t like me i guess, Lol. changed my password, I even got booted off the site for a couple hours today.

Thank You again, very much appreciated.

Ben

[fixbear]

If you have a DVOM that will read milliamps. you can check the gas valve. If not, you can still determine some certainty what is happening. Before thermostat heat call you should have approximately 750 milliamps output of the thermopile. Turn the thermostat up and it should remain above 250 milliamps. The valve will open, and the voltage should go above 500ma. (It takes more to pull in the valve armature than hold it.) I’ve replaced a lot more valves than thermopiles. What happens is the plunger that opens the valve binds with age and heat. Especially if the gas line has dirt in it and no drop tee to protect the the valve. Then it will want more power to open than is available.

You said you had dropped the fans on the evaporator. If the compressor was running at the time, you did this, the coils should have frosted up all the way across in about 4 to 5 minuets as there was no air going through them to heat the refrigerant. Indication of low charge if not and condenser is working.

You are right about my first post. I have no idea what happened to it. But basically it was a field quick determination to find what is wrong without entering the system.

Caution, when touching the tubbing it may be hot. above 212F. So always wet your fingers before touching the compressor discharge. or use a clamp on thermometer. Start by determining if the fans are running. both condenser and evaporator. Next feel the condenser discharge (bottom tube). It should be just above the room ambient temperature. Next feel the top tube. It should be very hot. Normally about 120F to 150F. This tells us that the high side is working, compressor is running, and that there is a reasonable amount of refrigerant in the system. If the lower tube is hotter than near ambient, you have a condenser fan or air flow problem.

Now we look inside. All fans should be running and at the same speed. If you look at the back of the coil, it should be clear or have minor frost/ice at the inlet of the evaporator. Excessive ice means low air flow, leaking fan housing or bad door gaskets. After 20 min of running, it should have a small amount of frost over the whole coil.

I lot of modern coolers have not only light switches, but also stop the fans when you open the doors. They are a double throw switch in series, so When the doors are closed, both switches have to send current to the fans. Either door opening will stop the fans and send current to the lights. So when you look at the back of the evaporator and see a lot of frost or ice, one would want to check that the fans are running. I’ve come across a lot of foreign made ones that the switch contacts fail intermittently.