Continental Freezer model F2 404A refrigerant not cooling properly. Replaced cap tube, and filter drier, evacuated, and charged. Box temp not going below 32' and ice forming at beginning of evaporator. Ambient 85 to 105', condenser temp at 30' above ambient, evaporator pressure 24 to 30 PSI. Nothing I have tried is improving the temp, or pressure. Customer irate. I used a BC1 cap tube (dual feed) at recommended length of 56' each. Did not work, shortened tubes by 1/3 = 19". Still the same. What else can I do?

sounds like you covered most all bases. without knowing pressures, I would look for a possible restriction. Since the TXV was replaced, are you sure you went back with OEM? If refrigerant was weighed in, was the drier an oversized one? It's rare but I have found some units that just don't cool right with the factory weigh in charge. You may want to try to charge by pressures. If it has a condensate pan with a hot gas line, be sure it is dry before trying as this effects the pressures. Good luck. Looking forward to hear about the fix.

Normally, laying a refrigerator down will cause any debris or sediment to float through the tubing and eventually end up in the filter drier which contains silica beads to absorb moisture. Debris will then plug up the drier. A technician will be required to evacuate the sealed system. He will then cut out the old drier and braze in a new drier and recharge the system.
There is usually no guarantee that this will fix it because if the debris is large, it may clog a capillary tube and render the unit un-repairable.

I’m happy to assist further over the phone at https://www.6ya.com/expert/david_dc2f9e0a44104720

You have non-condensables in the system.

1.Recover Refrigerant

2.Change Drier

3. Evacuate to 500 Microns

4. Weigh in charge

why yes there is. Generally speaking, the head pressure should be around the "ambient +30" rule.
That is, measure the entering air temp to the condenser, say 75 degrees. Now add 30 to that and get 105 degrees. Look at a P/T chart and see what the pressure is for that temp which is about 253 for R-404-A.
The evap on a freezer leads the load so, as a general rule, the evap temp is going to be around minus 10 degrees to get a 0 degree box. Coolers are different. So, the pressure for a minus 10 evap is around 25 or so. But the unit has to be close to operating temp. If the box is warm, naturally the pressure is higher. And what influences the pressure is whether or not it's a TXV or a cap tube system.
If a TXV and no receiver, charge by subcooling. If a receiver, fill by sight glass. If Cap tube, charge by superheat.
Hope that answers your question.

Hi,
There are a few reasons why the refrigerator part will not cool...here are a couple of tips that will help you to figure out why the refrigerantor is not cooling...

Refrigerator not Cooling or Fridge not Cooling
http://www.fixya.com/support/r3662945-refrigerator_not_cooling_or_fridge_not

How to Defrost Refrigerator Defrost Timer Problem
http://www.fixya.com/support/r3771673-defrost_refrigerator_defrost_timer

heatman101

There are some drop ins, but none are marketed for consumer products like this. Also, a new unit will use so much less electricity that you'd save enough money in a year or maybe two to pay the cost difference between the cost of recharge compared to new.
And....many times recharging units like this don't last long because they normally use a capillary tube in the system (instead of a thermal expansion valve). The cap tubes have a very small opening, and when the system is opened and recharged even very small contaminants can clog the cap tube later on and then the unit won't work.
Best bet is to get a new one.

Hi,
When it gets very cold the gas (freon) in the refrigeration system shrinks....because the properties that make cold also work against you in this case...when the gas shrinks in volume it then does not work properly anymore...the hot gas does not turn back into a liquid but stays as a gas and because of that it does not cool when going through the expansion device...ie. cap tube or expansion valve. If you were to keep it in the cold all the time you could add a bit of charge to make it work, but then if you move it to warm or the weather warms... now you are over charged... just one of those "no win" deals...
They don't make these things to run in extreme environmental changes..they like it a consistent temp. all the time...

Heatman101

The pressures depend, somewhat, on the expansion device,i.e. a TXV or Cap Tube. Take a pressure reading, then convert it to a temperature. The evap temp should be right at 10 colder than the box temp. Remember, heat flows to cold so the evap has to "Lead the Load" in order to cool. In many cases, the condensing pressure is usually ambient temp, plus 30, then convert to a pressure. These are general accepted practices that have been used for many years.

Hope this helps

Check out "victory-refrig.com" for manuals, diagrams, etc.
Cap tube systems are "critical charge systems". Can be difficult to get right. You did not mention pressures that you had. The split on the evap vs.box temp is almost always 10 degrees for freezers. If you want a -10 box, your evap needs to be -20. As a general rule of thumb, you want the high side to be "ambient +30". This seems to work most every time. Your problem might be operations related. Them leaving the door open alot and so on. It could also be a problem with the evap fan or the control to it. It could also be that since there had been a problem with the unit, they are now constantly checking it. Could be checking during a defrost cycle. When your box is at 0 degrees, your pressure should be about a -10 and no less that a -15 degree for the evap. You may have to babysit this thing and see how far it will pull down. You may have a weak compressor. Also, I have had many Hobart freezers fail due to dirty condensers. This causes the oil in cap tube systems to gel and clog up the cap tubes. The only fix is replacing the cap tube. There are alot of variables here so be patient, it's not going to be a quick fix. One last thing, since R404A can fractionate, you really need to pull the charge out and weigh in the correct charge with virgin refrigerant. This will eliminate 2 things. 1, it will ensure the correct amount of refrigerant and, 2 no chance of having a poor mixture of refrigerant in the system causing inconsistant readings and performance.
Hope this helps. And remember, cap tube systems are performance measured by the amount of superheat just prior to the unit making temp and cutting off.